I went unholy when i made my dk. I agree, ya'll ain't loyal, UFL and so on.
In terms of current dps, scaling and so on, unholy has been ahead since 5.4.7 (or whenever the buff to unholy might happened). 2h Frost can't even compare, DW frost is still a bit more competitive, but the only fights I've been consistently beaten by frost dk's is garrosh (not even spoils, but i believe a GOOD DW frost should beat me in theory on spoils) and that's usually just cause my trinket procs + runeforge refuse to reliably proc together on the pull. And that's just me, and that i'm usually up against DW frost's who are a good 5+ ilevel above me.