Well, if one or all of you are boarding and planning on sticking together, then Alta and Deer Valley are out... both are skis only.
Other than that, I think any of your options are cool. Park City Mountain Resort has great terrain parks and some wicked blue and black groomers to rip, but nothing terrifying. If you want to get more gnarly, aim for Snowbird. Brighton has some great park stuff as well, and is on many days a haven for boarders. Solitude, slower lifts but honestly, never ever a line nor a crowd, so that's a good choice too. Canyons is a fun place, some have their complaints about it but purely looking at it from a ski or boarding view, theres a ton of terrain to satisfy most anyone there if you look hard enough.
North of SLC, you could aim for Snowbasin... I love that place and I don't think i've ever stood in a lift line there, either.
The bottom line is that if you have a week, you can hit most or all of the ones listed above. Sh*t, if you want to try something unique, go to Sundance one day too, down in Provo Canyon. All these are within an hour or less of SLC unless there's a blizzard! Lemme know when you go. If i'm around and not out of town on business i'll probably be up there on several of the Dec. weekends... usually, I am.
And there are tons of peeps on here who also are out and about all over Utah. And many of them actually LIVE there, and i'm sure can add to my novel!