Here's the problem. I love movies. Okay, maybe that isn't a real "problem", per se, but it means that there are too many movies to choose from. And if you ask me the same question six months down the road, my answers may change. Kind of depends on which ones I remember first. Movies I have watched repeatedly might qualify as favorites, OR it may be that they are just on TV more frequently.
But I'll go with that definition for now. In no particular order:
Alien
A Bridge Too Far
An American President
The Great Escape
Hunt For Red October
Jurassic Park
Jaws
Fort Apache (actually, any one of the John Ford cavalry trilogy)
In Harm's Way
Midway (the original)
The Magnificent Seven (original)
Clearly I can't count. But I'll quit there.