I think it depends on what you want to shoot:
Landscape: Southern Utah / Great Salt Lake
City: Ogden (There are a TON of old buildings and railroad)
Events: Salt Lake Arts Festival, Park City Arts Festival, Provo Freedom Festival, almost any of the small town 24th of July celebrations, Larry H Miller Speedway
Other: Utah has a slew of ghost towns that are still around in some diminished form or another. Also, hit Flikr for Utah photag groups and join them for a bevy of other venues.
There's a passel-full more...I'm just not the person to tell you everything else. Maybe some of the others will add....