For upland bird, I have to say that chukkar is about the best I have ever eaten. Pheasant and grouse are pretty good as well. For big-game, buffalo. For big game that can't be easily bought in the store, my vote is elk.
On the flip side, I don't like duck or goose, which explains my not hunting them at all. I know a lot of people think a fat goose is manna from heaven, but for whatever reason I have just not ever cared for it. I have tried many, many preparations in hopes that I find something about goose that I like, and I ahve yet to find the one that works...