I loved Cloak & Dagger as a kid - just downloaded it again and it's still great. I still yell at the kid to pick up the gun, just like I did when I was 8.
La Femme Nikita is probably my favorite all time action movie, though the subtitles on some versions are really bad. The old VHS subs were pretty accurate.
I guess Starship Troopers is sci-fi, but it has a lot of action, and is another favorite. I also like the Bourne Identity, Ronin, Bullitt (anything with a good car chase), Heat, Collateral was okay, Payback, Sin City was great, Snatch and LS&2SB, The Getaway (McQueen), Terminator, T2, True Lies, Commando, Red Heat, Raw Deal, etc., and I actually liked The Last Action Hero (I think I was the only one). Let's see... Leon the Professional, The Usual Suspects was kind of action-ish and I love that. Eh, there are more, but I'm tired of thinking now. Time to watch something instead of thinking about it.