Most un-PC - a carp. It went belly-up in a scak on my mate's fishery, so we barbequed it. The poles have it for crimbo, but I'm sticking with turkey - it was a bit fatty and tasteless.
Pike's tasteless, grey mullet is like MFI furniture - looks nice, but when you get it home you find it's completely tasteless.
Eel's bloody good, perch is cracking, zeds are nice. Gudgeon's lovely - floured and fried is best. Minnow is edible done like whitebait.
The best fish in the UK is a quivering-fresh mackerel grilled. And they taste nice raw, too.
And I like a really big skate wing with black butter.