One of my favorite online retailers for knits is The Fabric Fairy, especially if you're sewing for little ones (or like bright colors!) The owner is really nice and helpful, she can probably steer you in the right direction if you tell her what you're making. I believe the website is
www.thefabricfairy.comThe last time I was in Purl, they also had some great Japanese import knits, which are probably on the website. Expensive, but cute
www.purlsoho.com
, Varenia