Herring, mackerel and sardine are usualy ungutted at the nearest Tescos to me, my fish monger gets in pretty much all the fish ungutted and then does them when people buy them. I normaly take them as is and some fish he won't do - like the wolfish I had a while back ( having skinned it myself I can understand why, they make eels look delicate ). He'll also do most game as is but if you've never tried it before I wouldn't start gutting on something that's been dead for a week and still has all its feathers.
Realgar