Wow...how funny. I'm in the same exact boat as you. I'm a third year finishing up my first rotation (surgery, no chance in hell ill do that one) and have my tentative eye on either IM with a fellowship or anesthesia.
On the one hand, I find IM really interesting (especially cardio and GI) and love the fact that you really learn about a little of everything out there, but anesthesia also seems really interesting and I like the fact that they do all those little procedures that seem lots of fun. Of course if I were to go into interventional cards or GI there are procedures involved there too. I like the OR, but would never want to be the surgeon in charge of steering the ship and standing there for hours on end, working 80 hour weeks. Internal medicine has its mix of characters from what I've seen, from the very nice to a-holes that could very easily fit into surgery just as well. EVERY anesthesiologist i've met is super chill, funny and overall seems like a great person to have as a coworker. Everyone in that specialty seems to be happy with what they do. In medicine this varies. Pay is more or less equal if I were to do anesthesia or one of those two IM fellowships so this is not a big factor to consider. Hours in medicine seem to be worse, and work can haunt you long after you drive home, whereas in anesthesia you are DONE once you leave the hospital for the day. I think I really like that. In medicine you sit and have time to think about what comes next...in anesthesia as mentioned above things can change in mere seconds and it requires quick action on your behalf to keep an easy case from crashing terribly. I kind of like both, although sometimes I wonder if I'll grow to hate all the paperwork in IM. I like keeping on my toes, but those "nightmare" scenarios in anesthesia frankly scare me somewhat. For some reason I imagine myself in charge of a big fat guy, impossible to intubate and being completely incompetent as I sit there and watch the guy desat himself to death...Although I guess its less so if I remember that obviously that's what residency is for...to prepare docs to deal with those things.
Man. What a give and take. I'll cut my ramble off here (a result of being tired and stressed, and contemplative today), but those are the things that flood my head when I try to debate between the two. Keep the discussion going guys, I enjoy hearing others' viewpoints.