I know what people mean about not considering catchy as great since people say it about terrible pop songs. I hate to call a song I like catchy, but sometimes it's true and doesn't mean the song is lacking in quality. I'd say parts of Through The Looking Glass (first Symphony X song that came to mind when I thought of ones that had been stuck in my head) are catchy, for example. Communion And The Oracle, Of Sins And Shadows, Fallen, Eve Of Seduction, The Edge Of Forever - all those could be described as being catchy and none of them are bad for it, in my opinion. Often by catchy it's more about just a really good melody that sticks with you, rather than just being a really one dimensional song where all it's got is that "catchy" hook and nothing more.