Splinter Cell isn't really made for online in my opinion... For me it's more the submersive storyline and excellent single player that drives me to these games. DA however is probably my least favorite of these games. Don't get me wrong, it's still an amazing game, but when you contrast it to say, Chaos Theory(my favorite game of all time

), it just lacks in almost every detail... The direction they took with the story is one they should never have taken with SC.
Edit: Conviction does look pretty sweet however, being able to use objects around you to beat foes into submission and excellent hand-to-hand combat.