This thread is chock full of geotards. Hawaii is getting way too much love. Oahu is too overrun, the big island is too bland. Maui is very nice, but St. John (yeah it's part of a US territory, not a state, so what). I haven't been to Kauai, so I guess I can't pass full judgement, but still. Plus it's too isolated.
Colorado is nice, but for mountains I'd rather go to Idaho, Montana, or yes, Utah. Central Utah blows, but so does eastern Colorado.
From a geographical point of view, listing anything in Florida is an absolute joke. Yeah it has coastine, but you'll find better beaches elsewhere, and interior Florida is flatter than Kansas. Seriously.
I'm really partial to the northeast myself. Washington state has some nice varried terrain. I love the Olympic Peninsula and the Cascades.