I have been using Kangaskhan for a while now, and I really like it, it has a number of uses, but it makes for a really good bulky stall attacker, like a poor man's Toxicroak. The set I have had most success with is this:
Kangaskhan (F) @ Muscle Band
EVs: 212 HP / 248 Atk / 24 Def / 24 SDef
Adamant Nature (+Atk, -SAtk)
Basically, the idea is to get 101 Subs that can't be taken out in one shot by Seismic Toss, then recover with Drain Punch. Return is for it's STAB and Sucker Punch is good synergy with Subs, as the opponent is going to try to knock down the sub to use toxic etc. Sucker Punch also serves as a great Priority attack when dealing with the new wave of bulky Psychic and Ghost types. This set up is mostly for dealing with walls like Chansey, Frillish, Spritomb, etc. Muscle Band adds damage to attacks, and subsequently recovery with Drain Punch. Leftovers is also viable, but I play with Item Clauses allot, and leftovers isn't a requirement.