Even among the brands that are the leaf and not simply raspberry, the flavors differ. Yogi has been my least favorite and is what I bought most recently unfortunately. I wish I remembered the brands I had previously.
I got mine online, since my tiny little town doesn't carry it anywhere. I got it on Amazon, a pound of loose-leaf from Star Botanticals for $12, including shipping. The seller was Vitacost. They have their own website, and I have a 20% off coupon "for a friend" if you'd like it. Their shipping was super fast, shipping out of NC, and their customer service was beyond excellent when my usps carrier lost my package, they immediately UPS'ed another, no questions asked, and I got it two days later!
Re: Best Red Raspberry Leaf Tea brand?
http://oi62.tinypic.com/2w73hq9.jpg
This!