Good racials - good all game and genuinely useful
Breton
Orc
Average racials - only good at the start or meh bonuses
Argonian
Altmer
Dunmer
Nord
Bad racials
Bosmer
Khajiit
Crap tier racials - Might aswel not have any racials at all
Redguard
Imperial
I dunno. I agree with Breton and Orc racials usually being the best.
Histskin is an oddball, Argonians are really built for thief builds, but Histskin isn't really a life-saver unless you have a lot of HP behind it to pump -- a la tanky warrior builds.
Altmer racials can wildly differ in usefulness -- if you're not going to be using a lot of cost-reduc gear, it could help, however; if you do use a lot, it can wind-up being literally worthless.
Dunmer racials kinda svck, actually. I mean, the passive fire resistance is nice, I guess, but that power suffers the same issues destruction spells do: no scaling.
The sheer amount of frost damage in the game makes Nords nice. Plus that battleshout is great for reprieves or getting away.
Bosmer... I've not tooled around with 'em much. I'll refrain from really commenting outside of that, again, disease immunity is pretty easy to obtain.
Khajiit racials are, basically, useless. Night-eye is very meh, and extra unarmed damage is overkill when brawls are extremely easy to win anyways. Obvious race of choice for monk characters, though.
Redguard's power can actually be extremely useful. Mayhap not so much for warriors that abuse the "drain 1 stam" mechanic, but still.
Imperial's Voice of the Emperor is awesome, from what I've seen. Now, if it suffers scaling issues like a true illusion spell, then, I could see where one could say it's useless. I've only gotten an imperial up to level 20ish or so, but from what I saw, again, Voice of the Emperor is pure awesomeness.