yeah slaking... also, i'm a big fan of miltank. i used to have a miltank with a King's Rock moveset, so it'd cause a lot of flinching, and another one that was a defensive tank. i just love miltank because it's so adjustable to different kinds of usages.
tauros is pretty good as well. has a high attack and speed. clefable is pretty awesome as well. you can go many different ways with clefable.
kangaskhan is good too. can really only be used for physical attacking, tho.
i know this one is going to sound crazy, but dunsparce with serene grace is greatness. put a king's rock on it with rock slide and headbutt (bite does will with this as well), and you have endless flinching. problem is it doesn't have much speed, and other than its HP, its other stats are not that great as well. body slam on dunsparce is not as effective, but can be harmful. it can also learn astonish for flinch, but it's weak.
granbull has a lot of attack. nothing else so special about it tho.
ursaring is sorta tankish, but also has decent hp and a high attack. with its ability, Guts, Ursaring will become a lot stronger in D/P. with a Flame Orb attached, its base attack stat goes from 130 to 195 during battle. it will have burn on it, but that not only makes it stronger, but it prevents it from any other change of stats, and with a base HP of 90 attached with HP EVs, ursaring is set to cause some damage for a good bit of time.
PorygonZ... goes without saying how good this thing is.
stantler, like miltank, is a very adjustable poke, and is fun to construct. doesn't have much potential in competitive battling, but it's decent nonetheless.
zangoose... really not that bad, but definitely not that good.
hope that helps.