The right choice for you?

[Intrepid]

roleplay should be completely independant of the mechanics.

Sort of. I've been in a 4E D&D game for two months and find that non-combat interactions are hard to come by. Other games I've played go the extra mile to provide skill-based mechanics (Shadowrun's skill web comes to mind). The former makes a great hack & slash game but the latter is better for storybuilding.

[realitycheque]

I think we have a difference of opinion around the meaning of 'roleplay' - I don't think of social interaction with NPCs as roleplaying (especially after playing Exalted with it's social combat rules), roleplaying to me is having a fully fleshed character and playing it to the best of your ability, quirks and all.

Having a good GM helps.

[Deathula]

Beer and a good DM to get things started.
Also try starting off at lvl 3 or something. Gives the G side a bit umph, and to me makes it easier to get into the game/story that a GOOD DM has created