Quote Originally Posted by gRomoZeka
"Дельфины мне нравятся" is perfectly ok.
Well, it's OK, but not perfectly OK, in my opinion. The construction "я люблю" is much more common in Russian, and actually, "мне нрави(я)тся" could have a bit different meaning. "Я люблю" usually means I like something generally; for example: "I like apples" (I generally like to eat them). "Мне нрави(я)тся" usually means I like something concrete. Say, I bought some beer, and I'm drinking it, I can tell to my friend: "Мне нравится пиво". That means I like this beer. In English it would be "I like the beer", "I like the apples".

And then again, about the word order of "Дельфины мне нравятся". It is okay, but only in the context when you want to emphasize that you like dolphins. In English it would be something like "As for dolphins, I like them". In Russian, the thing you want to emphasize, usually is situated at the end of the sentence. If you say "дельфины" in the beginnig of it, that means you've already mentioned them before. Of course, the rule is not strict, and the intonation means much in the spoken language.