How close is relatively close? It kind of depends where you want to shred.
Boreal, Homewood, Diamond Peak and June Mountain (near Mammoth) all partnered to offer tickets to each other's resorts which is pretty sweet if you want to check out several of the under appreciated resorts in the area.
The Epic Local pass is probably the best bang for your buck for more well known resorts (Northstar Heavenly and Kirkwood)
Squaw/Alpine has always been my favorite but it's pretty pricy this season in my cheap ass opinion.
This is a shameless plug but I'm working on a round of of the best season pass deals for the season that will come out in the Tahoe Weekly Magazine sometime in early October. (There will also be around of of ski/snowboard movie premieres in the same issue so it's a pretty good one to check out).
Skis and boards that don't suck, by women for women.
We're the one's we've been waiting for