Best: Erebus, assassin erebus to be exact, I don't know why i ever went minion, i just don't have the ability to micro my minions, i think if the monks, clerics, etc weren't in the game i wouldn't mind a minion build, but the fact that i tell my nightwalkers to stand there and take the tower hits, i can't stand having to click my monks back away from there *vented*
Pretty much any match that I don't like my teams odds, i go erebus, I mean, a stun, a tele, a lifestealing/slow, and 100% immunity to anything as skills, i mean, this demi was made to live forever (Vampire, DUH!) I just can't get enough erebus, and he is too much fun to play with! Erebus for god tier!!!
Second: would be whoever i am currently trying at the time, whenever i read a cool build, THAT is my secondary character, may it be a cool AA reg, or a non healing sedna (Don't bump it till you try it!!) but right now it happens to be Oak, he has some really cool abilities, and his shield is one of the greatest skills in the game IMHO...
Worst: This one I am not quite sure about, but i guess if i had to pick one demigod who I wouldn't play against Orcun_BL, it would have to be regulus, I find him alot of fun, and he is one of my most played DG's, but he just isn't that great, I have tried a number of builds with him, but then i always end up reverting back to Snipe/Mines, which is great and all, but not my style, i like to be doing very large amounts of damage at a time, i don't like setting up traps, just not for me...
DaBRUM