lordwow

The Office & House come to mind.

ER as well.

Rocketdog2000

Babylon 5
- I actually missed the first two seasons of this show when it was airing, but then had a friend convince me I should start watching it during Season three. Luckily he had the first two seasons taped (this was, of course, in the pre-DVD days), so I got to catch up quick.

Buffy The Vampire Slayer
Angel
Roswell
- We had no WB affiliate at the time, so all the WB shows would be shown at later, or odd times on our local UPN station. This was also in the pre-DVR days, so I could only watch or tape so many shows, and some things got missed.

Veronica Mars
- It got to the point, that when this show debuted, the only other thing I was watching on UPN at the time was Entreprise, as most of the other decent shows they had were gone. So for the most part, it was like I forgot that network even existed. Thanks to the magic of DVD, I was able to catch up.

Friday Night Lights
- Only recently got sold on this show via DVD.

TheKing

Lost (Bought Season 1 DVD blind, caught up in time for the Season 2 opener)
Cold Case
Without A Trace
Law And Order
Law And Order SVU
Law And Order CI
Family Guy (didn't really get into it until after it was cancelled, but before the comeback)
Two And A Half Men

Vipper II

Supernatural
CSI
CSI: NY
Medium
Alias
Law & Order
Seinfeld (more like season eight)
Frasier
24
Nip/Tuck
How I Met Your Mother
Dexter
Six Feet Under
Good Eats

lisadoris

Buffy (saw S3 on FX the summer before S7 and had to do some major back tracking)
Sex & the City (started at S3)
Stargate SG-1 (started with S9 and back tracked)
Veronica Mars (caught up with S1 & 2 the summer before S3)
West Wing (started with S2)

paradicelost

I can honestly think of very few shows that I started with at the begining of the series(i guess someone should start that thread).
Buffy and Angel i didn't start to love until after they had already ended.
Then shows like Smallville, i picked up the first season last august because Target had it for $20. I fell in love with it and managed to get seasons 2-5 a week later, then i got S6 when it came out and I set up a season pass for S7 and I think I got caught up after the third episode.
Supernatural, Married with Children, Sopranos, 24, (all the)C.S.I's, Deadliest Catch,Dead like me,Top Chef, Ben 10, Teen Titans, JLU, Criminal Minds and Dexter are all shows i had to catch up with season sets or InDemand(except MwC, i just jumped into that at S4) before the next season premiered.

movielib

Most notably Buffy and Battlestar Galactica, didn't watch from the beginning because of the first being based on a lousy movie and the second being based on a lousy TV show. Two of my favorite shows of all time.

Charlie Goose

ER - Started watching around season 6. Thanks to TNT showing two episodes a day, I was able to shotgun down 5 previous season in just a few months.

The Sopranos - Didn't have HBO for the first 3 seasons, so I watched them on DVD. When season 4 was starting, I had just gotten out of the hospital and decided to treat myself by getting HBO that day.

The Bus

24

And I didn't get into Lost until I bought the DVDs.

pilot

Only four shows I can think of at the moment..

The Shield - I can't recall how I got into it, but I think it was around the second or third season. I think I did a blind buy of S1, rushed to get S2 before Season 3 started to air.

Dexter - Never saw a episode until CBS started to air them. Watched the first one on CBS then went and bought S1.

The Wire - Didn't have HBO - I think I blind bought S1 and was hooked.

Rescue Me - I guess I never bothered to watch originally. Bought S1, then continued to follow..

Red Dog

Oz
Law & Order
Picket Fences
Coupling
Amazing Race
Seinfeld
Wings
JAG

rkndkn

I absolutely hate to join a show late -- and now with DVD sets, if applicable, I would catch up first before joining the airing season. (As I did with "Friday Night Lights".)

The only airing show I joined late (about Season 3) without catching up on DVD first (which was not possible at the time) is "Law & Order".

Burgundy LaRue

I latched onto CSI around S3. I caught on to Law & Order: SVU late too, but have since stopped watching it.

jpb07

Sopranos, Hells Kitchen, and The West Wing were my big ones. I was in and out of Veronica Mars the 1st season as well. Watched a few of the first episodes then due to commuting back and forth from Florida to California dodging Hurricanes, I didn't get back into it until the 2nd season. (I remember watching the first episode of Lost after transferring it from the DVR to DVD while in the air...I got through about half of it before giving up on it.) One other show which sort of counts is Gilmore Girls...the wife caught onto it during the summer of rerunning the 2nd season and it became weekly viewing after that. In fact, the only two things I remember from the day my son was born is that the new pope was elected and that I watched GG hours before he was born.

cookie5409

24
Missed the first episodes so I didn't bother to watch it any of them since I figured I would be totally lost. Bought the first season on sale intending to watch it & then sell it. Figured it would only cost a couple of dollars & I could take my time. About a year later I spent the weekend watching it & was hooked. By then it was up to season 6 on tv. Didn't watch any episodes on tv but bought sets & would spend the weekend immersed in 24. Love the show but hate the wait for new episodes.

NCIS
Missed the first couple of seasons but now never miss it. Taped a NCIS marathon that one network had recently for three Saturdays in a row. Got to catch up on a lot of episodes that were new to me

My Other Self

The Office
Hell's Kitchen
Law & Order: SVU
House (JUST got into it.. like this week.. watching Season 1 now, GREAT show)
Seinfeld
Everybody Loves Raymond
South Park
Curb Your Enthusiasm
Entourage

The only shows I can say I've religiously watched from start until current is The Simpsons, Family Guy, 30 Rock, and Oz.

Michael Corvin

I forgot to toss in Smallville. Watched the first four seasons on DVD before season 5 began and have kept up ever since.

creekdipper

Buffy, The Shield, House, Seinfeld, X-Files, STS9.

(Also tried a few episodes of ST:TNG Season One but gave up only to return for Season 3 & watch the last four seasons religiously).

Reading over everyone else's picks, amazing how many times the same titles come up.

Good thing their respective networks stuck with them (or they had respectable enough ratings to last until either the shows improved or we got a chance to catch on).

Probably wouldn't happen these days unless a show scored huge points with the prime advertising audience. Then it might get a chance to survive. Otherwise, it's Sayonara, Baby!

JasonF

For episodic TV, I'll almost always just start with the first season (on DVD if necessary). The only exception I can think of is Psych, which I just started watching a few months ago by catching the reruns on USA.

For reality series, I'll just pick them up at the begining of a season -- I started the Apprentice in Season 3 and The Amazing race in Season 5 (though I later saw seasons 1 through 4 in reruns on the Game Show Network). I also started Hell's Kitchen with reruns of Season 2 on Fox Reality (again, I've since caught up and watched everything).

Michael Corvin

If you look at most of the picks they aren't from the big 3 networks. Mostly shows from Fox, CW/WB, and cable channels. They can survive on lower ratings and actually have a chance to build an audience.

Kal-El

A couple:

Scrubs - 2nd season
House - 3rd season
Grey's Anatomy - 2nd season
30 Rock - summer break
The Office - summber break
NCIS - 2nd season
Brothers & Sisters - summer break
SVU - 4th season

Thos19

The Office
CSI
Jericho
Tudors
Dexter

kristina

I'd missed the first two seasons of Kathy Griffin's show, but tuned in for the third and upcoming fourth seasons... wish they'd release the previous seasons on dvd. all that's out there is 1 right now.

Geofferson

The Shield, Alias and yikes, The Sopranos are the top 3 shows I watched by circling-back on season 1 via DVD.

TimeandTide

Ditto.

Got lucky with The Shield. I had heard great things about it, so it was on my radar, and managed to stumble across a re-airing of the first two eps on Spike. I watched seasons one and two like this (a pair of eps. every Friday night), before getting impatient and buying the next few seasons on DVD.

Fell in love with Friday Night Lights late and caught up with the season one DVD.

Only other series I think I jumped on board after season one is 30 Rock. Now it's one of my top five series of all time.