I also didn't get into the first Splinter Cell. It bothered me that obvious headshots didn't always connect. A game has to aim right.
I love MGS 1 & 2. Hated the NES Metal Gear, though. Can't wait for 3, though it'll be tough to balance between it, Halo 2, GTA, and Metroid Prime 2.
Tenchu 1 and 3 are great games. Excited to see what's in store for pt. 4, though I'm bummed Activision dropped the franchise.