AV King
Slowking (M) @ Assault Vest
Trait: Regenerator
EVs: 252 HP / 252 SAtk / 4 SDef
Calm Nature (+SDef, -Atk)
-Ice Beam
-Scald
-Psyshock
-Fire Blast
So recently, I had a look at Slowking's base stats and thought he could do a very good job of being a Special Tank using an AV, with his 95 base Hp, 100 base SAtk and 110 SDef, and from what I've seen so far, I'm right. As to whether this set is better/worse than the Trick Room set I don't know, but this is very good for catching people off guard. To be honest, I'm kind of happy the AV can help Slowking break out of his usual TR set.
The set I run is simple, since I'm not the best competitive battler, but it's basically just 252 in HP and Special Attack, with a Calm nature and 4 Special attacks. The 252 Hp is so he can take lots of Special attacks, and a few Physical attacks (maybe), while dealing damage before switching out to make good use of Regenerator. As for the moves, I'm pretty sure they all speak for themselves. Scald for STAB and burn, Ice Beam for it's good coverage, Psyshock for hitting Special Walls, and Fire Blast because BURN BABY BURN!