I'll go with Nord, I went with Dunmer in Morrowind because of the region and I'll do the same here. I broke the mold with Cyrodiil, but Cyrodiil is the cosmopolitan capital and the CoC was just as likely to be any other race as Imperial. Besides Imperials are the least intriguing race imv, being so similar to RL Romans.
I'd like to play as an Argonian (I can never get humanoid faces right) but it will be a bit strange as I assume Argonians are cold blooded (although I may be wrong) and Skyrim is rather cold.
I will play all of the races at some point or another, to be honest. My main characters will most likely end up being a dunmer, a breton, and an imperial. I will probably end up beating the main quest as a nord for RP purposes, though.
A few years ago I made an oath-thing promising that I will play as the native race in whatever region any future TES games take place in. I also went back and made Imperial, Dunmer, and Breton characters for Oblivion, Morrowind and Daggerfall respectively.
So Nord for my first character. Although I'll probably make a Bosmer(favorite race) character at some point in time.
Probably Nord, but if they improved the Imperials, then I would be them. And I would create my class with Heavy Armor, Blade, um... and other stuff, maybe Destruction, depends on what they have.
It still seems Argonians are the more popular of the beast races. What is it about those lizards? I'm with the sugar trippers
BTW, some mod for Oblivion added a race called "Skyrim Khajiit", bigger and with fur like siberian tiger. Were they just fanfiction or do they exist canonically?