Good call for a thread.
A lot of mine come from one of my favorite "I just want to watch something" movies, Bad Boys 2.
First, there is the scene where the front engine Ferrari takes a barrage of bullets and continues the chase on the bridge. The partner on the inside shoots the dash board and doesn't take out anything past the firewall with his semi automatic rifle. This scene is also complete with Will Smith narrowly escaping being demolished by cars flying through the air. The Ferrari also can't catch up and/or pass a FULLY LOADED semi and the big SUV can't seem to out accelerate the same semi.
[youtube]
http://www.youtube.com/watch?v=yaLtd0H8G-s[/youtube]
Next, you've got the Hummer scene in Cuba where it and other trucks drive down a tiered mountain through houses that explode upon impact.

Also, if you watch the movie closely you'll see that in some scenes the H2 has a sunroof and in others it doesn't.
However, as far fetched as the chase scenes may have been, they weren't CGI and those stunts were all real.
Two of my other favorites are the original F&F.
This one is just silly:
But the big Charger flip- c'mon, that thing would've smashed its front end and Dom's forehead against the steering wheel leaving him unconscious. Theres no way it would have done a barrel roll!
That, and the endless amount of gears in any of the cars.
One more that does bother me is the dirtbike/semi truck chase scene in Terminator 2. I know its probably just a 125 or something, but it should have been able to EASILY out run a semi truck.
That, and when they get bumped by the semi, they don't fold underneath it and get squashed.