From the ones mentioned on this page, 1 is immune to Toxic, 1 has Heal bell / Aromatherapy / Natural Cure, and ones most common set happens to run Substitute
Chansey with eviolite. Pretty common stuff. It never dies and can softboil all day. It also has wish and toxic which are always good. Plus if you ever need it to attack it can use Seismic Toss and do okay damage. Shedinja actually can work pretty well too. As long as your opponents team has no fire, ghost, rock, flying or dark it can literally take hits all day. Plus with focus sash it can take two whole hits. I have trouble pulling off a Shedinja stall but I have seen some people do it amazingly. Its a big risk but sometimes it can pay off. Plus Shedinja can use swords dance and has an okay attack.
@luke Best Shedinja Stall is Harden/Substitute/Rest/Toxic But seriously, I tried a Hone Claws/Will-o-Wisp/2 attacks set once. XD I actually stalled out an Absol with it once because their only Dark attack was Sucker Punch. It was hilarious.
My favorite that works for me is an Eviolite Murkrow with Prankster ability 5 IV and 252 Def 252 SpD 6 HP. It gets access to Feather Dance to punish Physicals, Confide for specials, Roost to recover, and Toxic. That Wall is unstoppable and with that, one can safely switch into a Drifblim and use minimize and Stockpile and eventually baton pass for a max evasion, +3 def and SpD and if it is mega Kangaskhan, than double power up punch=double attack! Then proceed to sweep with sucker punch and dizzy punch(40% chance confusion I think) and a drain punch to get HP back. or use the belly drum Slurpuff for the baton pass...