First of all I can't beleive you'd even consider Conflict: Desert Storm.
Splinter Cell might be good to everyone else, but it never impressed me. I don't see how the graphics are as gorgeous as everyone says. Furthermore, "Sam Fisher" is about the worst name in the world, and he says horribly idiotic things.
I know none of that has anything to do with gameplay. But if you want to try it out, get it.
Ikaruga is easily the best game on the list, but chances are with the advent of how easy games are these days, most people probably wouldn't last more than 5 minutes in the game and would complain that it is too hard. Well poor babies. It's a Treasure game, a top down shooter, and it will absolutely blow your mind in terms of gameplay. It's defenitely my pick, because I'm really anxious to test out my skills to see if I'm as rusty as I could be.