My favorite stage with MK is Norfair. You can combo a lot here
Ummm...
you can combo with Meta Knight everywhere, anywhere, whenever within a certain percentage depending on the combo you are using.
On the other note
As I said Meta Knight is good everywhere but ginormous stages. But in reguards to counter picking it really depends on your style of fighting so I can evaluate more to try to find the perfect stage for you...
Q1: Do you have tendency to kill horizontally or vertical
Q:2 Do use prefer to or frequently spike/ meteor (foot stool) with Meta Knight?
Q:3 Do you enjoy the floaty fx some stages have? (exp. when Pk Stadium turns to flight mode)
Q:4 Do you use gliding a lot in your combos?
Q:5 Do you enjoy/ rely edge guarding or dimensional edge guard?
Q: 6 Do like ledges at all?
Q: 7 Would you rather like open space or areas with lots of stage hazards/ obstacles?
(very important trade off here for Meta Knight users since here they trade for no distraction/ obstacles in combos and not letting your foe run away or you get plenty of cover from projectiles)
Q: 8 Do you rely on a uneven main floor for your Meta Knight or do you like even out floors?
Q: 9 Do you platform to your advantages?
Q:10 Do you use stage hazards to your advantages? (Like throwing your foe at King Bublin at the right time to do damage
Q: 11 Do you feel moving stages operate to your advantage?
So yeah these are some basic question that need to be answered for a good evaluation since I feel blurting out a random stage i like to use wont be beneficial for you if your Meta Knight fighting style is different.