Socarrat (
www.socarratnyc.com) has great paella - locations in Nolita, Chelsea and Midtown East (haven't eaten at the latter).
Other favorite Spanish spots are Boqueria (
www.BoqueriaNYC.com) in Soho and the Flatiron, and Tertulia (
www.TertuliaNYC.com) in the West Village. Enjoy!