Crap, I was actually thinking of Metal Gear not Splinter Cell. I have Splinter Cell but haven't played it forever. I have to say hands down to Halo. We just played Halo (the original) and Halo 2 today and OMG they made a lot of improvements with the second release.
I have the Splinter Cells I love playing the co-op working together is fun I use to play Halo with my son lol he always ended up shooting me in the back coming to think about it he did that in just about every shooter game we played together lol
Love flying everywhere.