There have been some pretty obvious stuntmen in movies over the years, some hilarious others just ridiculous.

Moonraker- The opening sequence of Bond going out the airplane chuteless with Jaws on his tail, a pretty damn good sequence, very Bondian. Except the two guys fighting are not Roger Moore and Richard Kiel, but two other guys. ''Roger Moore'' has something suspiciously bulging underneath his suit on the back, but the real thing that stands out is the professional skydiver they made out to look like Richard Kiel's 7'2'' towering physique and distinct face, trying ever so hard to make him appear big when the poor sop looks like Ace Ventura with chipmunk teeth.

Predator- When Arnie is falling down that big waterfall, that entire continuous shot of the falling guy with the widow's peak is truly breathtaking.

Terminator 2- The famous scene of Arnie going off the ramp with his bike and landing, the stuntman looks so incredibly like Arnie except for the fact that it is done in slow motion with a clear shot of his face you can't help but see it is another guy, i guess they were too confident of his likeness!

A View to a Kill- I actually enjoy this Bond flick, being Roger Moore's swansong, he is pretty old, so you'll be deep in stuntman country.

Fight Club - When Edward Norton's character is thrown down the stairs.

Spaceballs

It'll probably get harder to 'see' a stunt person.. I found it interesting on Resident Evil 2 they basically had the stunt woman do her stuff, then digitally put on the main actress' face for closer shots.

Fast and the Furious.
you can see the driver is wearing a helmet.

Terminator 2 - already mentioned

The Ghost and Mr. Chicken: when Don Knotts (Luther) falls down the coal chute in the haunted house basement, you can tell it's someone else completely with a greased up head of hair.

Maybe not one for the ages, but I was watching McLintock! recently, there's a scene near the end where some wooden buckets fall down on John Wayne, yet it's obviously not him (it's his stunt double Chuck Roberson who also plays the sherriff). He's walking towards the camera and you can see his face pretty clearly. One can make good guesses when CR is doing the stunts because his face is kept away from the camera during falls, etc. (except for this one shot).

BTW, both JW and Maureen O'Hara do some pretty impressive stunts of there own for the film. JW jumps from a second story balcony onto a hay wagon (he was 56 at the time) and MO (aged 43) does a pretty serious backwards fall into a water trough from a ladder. Both of them slide down a steep hill into a mud pit during a lengthy (comic) fight scene.

The most obvious one in T2 for me is when the T-800 rides around the truck the T-1000 is driving. Right before he picks up John Connor off of his motorbike, you can tell that dude doesn't look anything like Ahnuld.

Another movie with obvious stuntmen throughout the film is Face/Off.

The one that always gets me is the way-too-short stand-in for Robert Englund in the original A Nightmare on Elm Street. It's like they got Warwick Davis filling in as Freddy for a few scenes.

Stewie: The Untold story, when stewie jumps out the window in San Fran.

I'm Gonna Git You Sucka, in which a portly middle-aged black woman turns into a slight mustachioed hispanic male actor in an afro wig. It's outstanding.

Every scene in the Avengers where Emma Peal is fighting. It's a man, baby!

To me the stunt guy in that scene had an incredible likeness to John Travolta. I don't know why but ever since I was a kid I've always thought the stunt guy looked like Travolta.

There's a couple shots in Die Hard where it's obviously a stunt man standing in for Bruce Willis.

The scene where he's fighting with a terrorist and the two of them fall down the stairs, you can get a pretty good look at the stuntman's face

Since this was one of the first movies that I watched on a weekly basis, I noticed the stunt guy a lot too. Before the fall down the stairs, you can get a good look at his face when his back slams into the wall.

I would watch this with a couple of friends and they would all go "Aw, you could totally tell that's someone else" when she does the flip. But when she starts beating the guys up, they just go, "Oh" and start laughing.

First thing I thought of...

Terminator 2 was the first thing I thought of when I saw the name of this thread. Obviously, the older a movie is the more "fake" the stuntmen look...bascially because no one envisioned 60" high-def home theaters and didn't worry about how realistic things looked prior to the mid-1980s or so...

Of course, most newer movies (assuming the budget is there) can use stuntmen and then graph the face of the actor onto the stuntman using a computer...

All that comes to mind is BEVERLY HILLS COP. The scene where Axel flips the henchman over the buffet.

If you pause the flip, the stunt guy is clear as day, and looks nothing like Eddie Murphy.

Funny thing is he (the stuntman) looks more like Richard Pryor.

I can't believe no one has mentioned the legendary "Black ACE" from "KISS MEETS THE PHANTOM OF THE PARK".

Ace changes race from action scene to action scene.

Benny Hill. When they throw benny off of a cliff, it's obviously a mannequin.

Strong Sad filling in for Strong Bad in Dangeresque.

Lee Majors, although he's the unknown stuntman

Any episode of Buffy: The Vampire Slayer. I know it's not a movie, but still sooooo obvious.

I always thought the skiing stuntman in the beginning escape in True Lies was blatantly obvious.