Hey Mythmere: I just downloaded Swords & Wizardry; great stuff!
But to answer the original poster: though I don't consider BECMI to be OD&D (especially not the way we play it), it was the closest option on the poll to what I play the most right now. Not that I dislike OD&D (see above)--it's just that the rest of my group wouldn't be down. I love me some BECMI.
We also play a sort of "pick up" 4e game when one of my players (who joins us via IM call) can't make it. We've been playing through the adventures which are...okay. I think the system lends itself better to a different style of play than the adventures implicitly promote: combat after combat (in my humble opinion) gets to be quite a grind after awhile; if the adventures were a bit more story/rp based, I think the length of the combats would heighten the sense of drama and excitement in the combat. Maybe. I dunno.