Melee combat.
I like that they have changed blocking to a reaction based system, and the flow to more of a 'taking moments of opportunity to strike' type. It reminds me of Condemned Criminal Origins, and that is awesome, because Condemned had the best melee combat I have ever experienced (even if it was occasionally buggy). It was adrenaline fueled and kept you on your toes, something I never really felt in Oblivion.
I'm of course basing this on the tidbits of info we've heard about it, but this is by far the thing I look forward to the most in Skyrim.
I'm also looking forward to seeing how dual wielding works and just what kind of tricks it brings to the table.
I gotta say I'm right there with you on combat. Visceral and realistic, I can't wait to get into some cool fights. Also love the direction they are going with bows this time making them more deadly (as they should be :celebration: ). This is probably the most exciting feature to me.
I think they hit the nail on the head with believable environments this time now that all of the NPCs have jobs that you can believe, and will have an economy (and through this perhaps we can presume they will have real food sources?). Just sounds like such a great idea, hope it's well done when we see it.
Another thing I am really happy about and fully support are the adding of puzzles to their dungeons and giving them an "Indiana Jones" feeling. I can't wait to see some of the puzzle mechanics they implement. My favorite games are steeped in puzzles, and I have yet to see a game use riddles very much but would love to see some of that in Skyrim.