my personal all-time favourite is the blizzard sorc. i play only hardcore, but it can be be done without gear and it works just fine even in full games
skills:
just put 1 in all prereqs till lvl 6
pump ice blast till 8-10 hard points, you should be 18 by then
it has insane damage, just chug those mana potions

at lvl 18, you have teleport and glacial spike, put the points in glacial till lvl 24 - glacial has the best crowd control in the game imo
after 24, you will be almost unstoppable, just make sure you have some skillpoints left to put points in cold mastery + blizz at the same time for a while
as for the gear, spirit sword, 3 pruby/psapphire helm, viper, soe, bloodfist/magefist, fcr rings, 3 pdia shield for me