Finally a question I have LOTS of expertise in! Gail, I used to stock a bar for years, it was awhile back, but I used to keep 3 or 4 as our staples, and branch out to flavoured ones during the summer tourist season (in your case, winter). IMHO, althought the flavoured ones are excellent, you are limited to what drinks you can make with them.

From lowest to highest in price, approximately...

Smirnoff
Absolut
Skyy
Stoli (my favourite!)
Grey Goose (higher end, more expensive)