Salmon roe is my hands down favorite, though I suppose partly because I can't afford the sturgeon varieties. Trout is pretty good, but I don't think it's commercially available (not that I've ever seen), still if you fish - it's better than wasting - my grandmother used to love trout roe. I've had milt before as well - an Italian friend fried some up for all of us when we were doing a fish fry with some pike and pickerel.

In other neat fish news; there's a store nearby that caters to much of the Newfoundland ex-pat community and sells Cod cheeks and tongues from time to time.