Argonian. I don't know about anyone else, but I found them to have the only faces that weren't excruciating to look at in oblivion (see: uncanny valley). Of course, I've been playing the lizardfolk since Morrowind, so that really isn't an excuse. Fluff and water-breathing mostly, I guess.
As for class, I either go with Destruction, blade, heavy armor and repair or marksmanship, stealth, illusion and lockpicking. Plus whatever else feels like it fits. I'm not sure how they changed the system tough, so I may not do exactly the same thing. I actually preferred Morrowind's system...