the tv
the type of cable (s video etc)
the dvd player

well, umm kinda hard to say.. are we talking standard tv or hd? does the tv have component inputs? use that if possible, then s video, if the tv will accept a progressive signal from a dvd player then that would be good.. but need a little more info..

i would say the tv first, then the cables, then the dvd player.

reasoning:

the tv is actually displaying the image, and whether its HD or not makes a big difference. if its a bad tv, nothing you can do will make it look good.

the cables can make a bigger difference than the dvd player. if you use composite, just about any dvd player, even super high end will look worse than a cheap player using component. (regardless of brand really).

most dvd players are pretty good nowadays (aside from apex, they still suck). if you get a reasonably good one, and do the tv and cables right, you will get a good image.

Like cowanrg said, definitely the TV first. This is what you view it on, it's the end result of the player and cables. A good TV can make a fair to middling player look great, where as a bad TV can't make a great player look good.

I'd have to go with DVD player 2nd, this is what's creating the image. The best connection and cables in the world can't help a player outputting a poor picture.

Lastly, cables. If you've got a good player and a good TV, the cables are going to enhance the picture and keep it clean. Preferably you'd be using component cables. Not too many TV's that fall into the 'good' category only have composite connections, and nearly every TV on the market now, good and bad, have Svideo connections. While Svideo is a decent jump over composite, decent equipment with a component connection is going to give you the best picture every time.

TV makes the biggest difference: it's like the speakers on a stereo, the buck stops there. Compare an RCA Scenium then watch the same hardware playing the same dvd on a Pioneer 730 or Toshiba HX series. The Pioneer and Tosh will both destroy it, there will be a clear difference.

Cables next. Component and digital inputs (DVI and firewire) allow progressive scan, so that's huge. S-Video offers similar interlaced performance. Composite looks washed out and crappy.

DVD player last, as long as you get one with reasonable quality. IMO, most quality brand name players are 99.9999% the same in terms of output. If someone can truly see the difference between a 1000 dollar Elite player and a 200 dollar Panny...suffice it to say either they're deluding themselves or have the visual acuity of a hawk.

the reason i can see the difference between a $1000 elite and a $200 panny, is becuase i work around this stuff all day. when you are around 200 different tv's all day, things just start to look different. two tv's that look the same to most people, look astonishingly different for me. its just because im exposed to the best and the worst. trust me though, i can put two tv's side by side, with different sources, and there is a difference. the average joe really cant see it, but if you know what to look for, you can see it.

but, it comes down to one thing, can YOU see it. if you cant see the difference, you are lucky, get the cheaper one

thanks for the replies i will say what stuff i use

27" rca tv its 1994 model year. its a good tv the picture is great and i like the color settings how black is black etc
it only has composite inputs though, i know thats bad but what i'm i going to do about that right?
how do i find out what picture tube in is my tv? like is it dark contrast etc or whatever because i like how this tv looks

apex dvd player it was cheap like 99 dollars its the 500 a i think. i can tell its poor quality because of the dvd in movies i watch compared to other dvd players the backgrounds especially dont look good quality i think thats the dvd player fault though

i have an older tv from a few years earlier (1991) its a GE 27" and it has s video surpisingly its older then the other one that doesnt have s video crazy right?

so what do i do?

What's your budget, what are you trying to achieve, etc. What are you happy with currently, etc.

I guess I'd start doing research and dertermine some things in a comfortable price range for you that sound interesting then going and trying to get a hands on with those items.