If I stick to common pies, my favorites would be:
1. sweet potato (similar to pumpkin, but usually better)
2. blueberry (if you use wild blueberries when making, it's to die for)
3. peach (good right out of the oven, and even better when the filling sets)
4. apple (so many options; double crust or single crust; vary the apple varieties; change around the ingredients)
5. lemon meringue (I prefer homemade, but store-bought will do)
6. pumpkin (homemade are excellent, but store-bought are almost as good)
7. pecan (probably deserves to be ranked higher, but I didn't grow up eating them)
8. key lime (some excellent ones in the Sanibel Island, FL area; I enjoy it as a change-of-pace, but if the ones listed above are available, I'm probably passing)
Pies I don't care for:
1. cherry (I don't like cherries, so why would I want a pie made out of them?)
2. coconut cream (I'm not that big on coconut, so I don't much care for this pie)
3. strawberry-rhubarb (I don't like strawberries or rhubarb, so why would I like both of them in a pie?)
Pies I like -- just rarely see (or make)
1. cranberry streusel (even better if made with wild cranberries)
2. chocolate (my sister-in-law makes a great one)
3. molasses
4. shoofly
5. several different type of Greek pies, which are made with phyllo dough
6. egg custard
Pies that always disappoint:
1. banana cream pie (I love bananas, so how could this go wrong; I'm just always disappointed)
2. mincemeat (no two seem to have the same ingredients)
Pies I've never had that I would like to try
1. mississippi mud (how different is it from a chocolate pie?)
2. chess (seems like a Southern pie that is quick to make, and tasty)
3. water (doesn't sound all that great, but it seems to have been popular during the Depression)
4. persimmon (another one I've read a lot about, but have never seen)
5. bean (sounds as though it's similar to a sweet potato in taste, so I'm curious)
And the above was off the top of my head. I'm probably forgetting quite a few types of pie.