However, the Tetons are beautiful as well and Jackson Hole is a nice mountain town as well.

I think there's less pretentiousness in RMNP though as all the stars go to Aspen or Vail and not Winter Park or Grand Lake.

Night life will be limited. Neither Estes or Granby are ski towns, therefore nobody goes there in the winter. There is no longer a ski area in RMNP, the old Hidden Valley ski area closed many years ago.

IMHO – the coolest thing to do in RMNP in the winter is climb Longs Peak. It's a day hike, providing you start slightly before sunrise. There is an old hotel in Estes called the Stanley Hotel. It was a candidate location for the filming of the movie The Shining. I'm not sure if they keep it open in the winter. Search flickr for the Stanley Hotel, I'm sure there are pictures of it there.

I certainly wouldn't spend big $ to go to RMNP in the winter. Not sure I'd spend big $ to go there in the summer. It's not a destination, more like a must do side trip when you come to Colorado.

If your into skiing, go to Winter Park, then you can venture into the western side of RMNP if you want. Winter Park is the closest ski area to Granby. If you want to hike Longs Peak, you will have to come in from the east side (Loveland) in the winter.

Your definition of winter activities is very important. If you mean downhill skiing, then the western slope area (Aspen, CO and surrounding areas) is your destination. A bit pricey, but the skiiing and nightlife are outstanding. From there, you can see what is open at RMNP or another nearby state park for the wildlife you seek.

RMNP has very few winter activities and no nightlife because it's a National Park. Looking here, a vast majority of its' roads are closed in winter:
http://www.nps.gov/romo/planyourvisit/road_conditions.htm.

The Grand Tetons are an outdoorsman's dream, but there is no nightlife. Skiing is still very good and much cheaper than in the western slope area. More information here:
http://www.wyomingtourism.org/cms/d/ski_report.php

Additionally, Wyoming has a lot more opportunities for cross-country skiing, allowing outdoor recreation while being alone with nature on your own pace.