God I could list hundreds, but here goes:
"They cut the power" scene in Aliens, amazing.
Police Station shootout in The Terminator
Cyberdyne building and subsequent chase in T2
Battle for Helms Deep LOTR:TTT
Battle for Gondor LOTR :ROTK
X2-Nightcrawler in the WH and Wolverine in the mansion
Spiderman 2-Both fights with Doc Ock
Hellboy II: Troll Market sequence and BPRD vs The Golden Army
King Kong vs 3 V-Rex's
Robocop shootout in coke factory and vs Ed-209
Office shoot out in Die Hard with Bill Clay, aka Hans Gruber
Cab scene in Die Hard With A Vengeance
Superman saving the plane in Superman Returns and lifting New Krypton
The end battle in Mission City in Transformers, AMAZING scene, the whole thing was just brilliant and made me feel a little kid again.
Tank Desert scene in The Last Crusade and Airplane sequence in Raiders
Hulk vs The Military in the desert in Hulk.
Millenium Falcon chase in Empire Strikes Back, End battle in Return Of The Jedi.
Forest scene in First Blood with Rambo stalking the cops
I could probably think of 100 more, but thats all i can come up with at the moment.