MGS was great in virtually every respect. The codec scenes were interesting enough and the story wasn' t like a bad soap opera it was actually very cool.
MGS2 started off VERY well, the tanker mission with Snake was sublime and again it made sense. The Big Shell section was passable, but got wierd and over the top the further you got in, ...the Arsenal Gear part was rubbish!
MGS3 was bad. Some interesting gameplay enhancements weren' t enough to save it from a stupid storyline, the worst dialogue in the series and general naff humour.
The cutscenes are always well done but Kojima would have stopped directing the games ages ago if Sony weren' t paying him shitloads to continue doing them. His boredom with the series is obvious.
Splinter Cell on the otherhand keeps things down to earth, with plausable plotlines, excellent dialogue, but rubbish cutscenes.
I adore the Splinter Cell games, and the multiplayer components that started with Pandora Tomorrow and came back much improved in Chaos Theory are a work of art, requiring REAL skill.
When MGS was released it was all about stealth, something Kojima pushed quite hard, ...but when Splinter Cell turned up and kicked both Tenchu and the Metal Gear games in the teeth, essentially beating them at their own game (pun intended), MGS was no longer about stealth but rather dynamic well thought out stories and repetative boss fights.
I have tons of respect for Kojima, i think he' s a great artist, ...but i' d much rather see him turn his talents towards anime than any more MGS games!