Here is a good post on chowhound:

http://chowhound.chow.com/topics/338331

It's been over a year since I moved from Kampala but for traditional Ugandan food (particularly Luwombo and chicken stew) I like St Anthony's near downtown.

For me the best food in Kampala is the pork joints, I favored Zanzi's in Ntinda but everyone seems to have a different opinion. For the most part, they're all good.

Emin Pasha is definitely good as is the Serena (I had a Christmas Eve dinner at the Serena that was as good as I've had anywhere).

The food court at Garden City is actually pretty good and I really liked the Shewarmas at the lebanese place against the back wall. The come with this garlicky cream sauce that is worth the price alone.