Enemy at the Gates is amazing.
Sniper starring Tom Berenger and Billy Zane is also a nostalgic favorite.
Saving Private Ryan isn't a sniper film, and neither is Lone Survivor, but both have great firefight moments that involve some sniping scenes and/or characters with sniper rifles.
Clear and Present Danger has a great sniper training scene early in the movie with Raymond Cruz (Tuco from Breaking Bad.)
I remember liking enemy at the gates alot. Does Lone Survivor count as a sniper movie? And Phone Booth was okay.
I don't consider Lone Survivor a sniper movie, but for this thread why not. Two of the four SEALs on that mission were snipers (Mark Wahlberg and Ben Foster's characters) and carried sniper rifles, and the movie does a good job depicting some longer range engagements during the battle scene.