Hailed by every stoner I know, Sour Diesel has got to be one of the best strains out there. The smell is amazing and super-dank, and it'll knock you on your ass before you finish the first bowl. It's a must try.
I just got done smoking some Death Star, and it's by far one of my favorite indica strains. The high is very relaxed, you'll find yourself stuck to your couch, mellowed out and looking for some good music to listen to. Highly recommended, if you can get your hands on some then go for it!
Hawaiian is a decently popular strain in Colorado, at least from my dealer, and it's a really good sativa with almost no body high. Lasts 2-3 good hours, and a really good strain if you want to get the creative juices flowing.