I had a heck of a time trying to finalize what alliance I would pick. I had a starter in all three, and honestly, I couldn't decide. I initially wanted to pick Ebonheart, because walking around Morrowind brought back such memories, and, most importantly, it has a dragon as a symbol!
The one I thought I would never join was the Aldmeri Dominion, because Thalmor are pricks and all that. But then I tried it, and fell in love with the scenery, the Queen, and especially Razum-dar. It's the Khajiit's homeland, after all, it may be rascally, but you can't help but love it.
Daggerfell is the one that made the most sense to me. It had more unity then Ebonheart, and more equality then Aldmeri. And Jakarn was more then enough to offset Razum-dar. But, lacking those things, the storyline seemed a little more of just random plots thrown together than the others. Just some random ultra bad guys attacking here and there.
In the end, I went with Daggerfell, but I do have characters in the other two, just in case.
Rune Fell- Dunmer Mag Sorcerer (DC)~The Adventurer
Runed Claws- Khajiit Stam Dragonknight (DC) ~The Tank
Rain Fell- Argonian Mag Templar (EP)~ The Healer
Dragon Talon- Bosmer Stam Nightblade (AD) ~ The DPS