Here are some tried and true sets from gen 4 UU, and I doubt much will change for it in gen 5.
Miltank @ Leftovers
252 HP / 4 Def / 252 SpD, Impish nature
ability: Scrappy
Curse
Body Slam
Milk Drink
Heal Bell
Miltank's high defense means that after a boost, it can shrug off most physical attacks, and after two it's impenetrable to anything physical except for STAB, boosted Fighting attacks. Scrappy lets you hit anything with Body Slam, and if big bad (insert tank-like Steel- or Rock-type here) try to stop you, you can often just get to +6 and whittle them down. Can support the team, counter threats, and sweep - an all around team player.
Miltank @ Leftovers
252 HP / 252 Def / 4 Spe, Impish nature
ability: Thick Fat / Scrappy
Stealth Rock
Milk Drink
Heal Bell
Body Slam
Support Miltank. Makes use of it's good stats and movepool, and unlike most Normal-types, it has resistances.
Miltank @ Life Orb
4 HP / 252 Atk / 252 Spe, Jolly nature
ability: Scrappy
Double Edge
Earthquake
Milk Drink
Heal Bell / Rock Slide / Fire Punch
Miltank is outclassed by many other Normal-types in terms of offensive stats, so if you're going offensive, make use of it's unique assets. Scrappy gives you nearly perfect two-move coverage, (it was perfect in UU except for Solrock and Lunatone), so take advantage of that to use some of Miltank's support options that allow it to differentiate itself, like Milk Drink and Heal Bell.