I'd say that all predatory will eat first fish they can find in their way. I've seen what can be found in stomach of a pike or perch. Here in Latvia mostly I've found:
1)Perch;
2)Roach (Rutilus Rutilus);
3)Ruffe (Gymnocephalus cernuus)
They all are common fish here. As you can see, perch and ruffe aren't as great pleasure as roach - they got sharp fins everywhere but seems like predators don't care.
By the way we got such fish as stickleback here (3 species actually but 2 of them are quite common - 3 spined stickleback and 9 spined stickleback).
Does it seem to be delicious? Not really... but fish eat them even it's not hard to find much
softer fish around.
