When I first started I did a lot of fruit.
I currently do Blueberry custard.
Flavorconcentrates brand Blueberry as a background flavor to vanilla custard. quite tasty. the best Blueberry I have found.
I have several peaches including the white peach. Black cherry... Cherry is a hard flavor but some black cherry as a background is nice.
I had avoided cherry flavors, too, because reviews were all over the map, but @chopdoc said I should try the FA black cherry, and he would never lie to me. So I did, and I really like it. In small amounts, of course. The most I use is 3% but that's in a mix with a bunch of other flavors (creams, tiramisu, cake), so it's not overpowering, just really nice. I like that it tastes like cherry, and not some kind of candy or other unidentifiable thing. Sniffing the bottle, it smells JUST like maraschino cherries, but that's not what it tastes like.