Read my initial review of Just Dance here
I don't know why and how I actually like Lady GaGa but I do.
Just Dance is this uber-catchy and even more infectious 'dance' track and I personally think melodically, it's brilliant. I said during my review of the song and album(it's on Pop Addicted!) that this song is like the basis of all the other songs on her album, like it was stripped into pieces and those pieces became the album tracks.
Then, I also noticed very RedOne elements, mainly because the song sounds a lot like Darin's Girl Next Door(thanks to Mel for pointing that out..) and the two songs have the same production team.
Now isn't that pure genius? haha.. The whole song is brilliant and the album is almost as brilliant, although I've gotten a bit sick of it.