I voted 'I love them all!'
SB: Just his attitude, BBB and super jumps make you wanna kill love him
SC: Well he is Sieg... moving on
SC2: Best NM ever. The voice acting+his appearance made him awesome to me. Also I believe he must have been very strong, but I havent really searched that
SC3: Very handsome, cool moves, suitable voice acting... Technically I started using him since this game
SC4: Even though he was like an emo, I liked him too, specially because of his moves
SC5: He's possibly my top favourite. I like the fact that he is back to his old self and attitude, he is nice and the voice acting suits him well (I wonder why Crispin Freeman gets so much love when Roger Craig Smith does a badass work here too). And as for his moves, it's been said here he's just 3B/WRB, well no he isnt, he has other useful moves too, like iagA, 66K (BE), name others, and an aGI others should watch out. Yes his stances have been nerfed, in overall you could say, since two of them have many flaws, but the rest two have strong stuff, like SCB/SCH KBE and SBH's aGI which leads to damaging combos. Also he isn't uninteresting since even a blocked 3(B) could lead to 50/50 situations (against most chars), in which you and your opponent should stay alert. I believe he is quite stronger/better than before...