I placed two seed orders the end of January they have finally all arrived. I ordered tomato seed from the Tomato Growers Supply since that is where I have ordered in the past and they have a great selection.
I also tried a new-to-me company, Kitazawa Seeds for some beans, peas, and onions. They are based out of California and specialize in Asian vegetables.
Ed Hume Seeds is another great seed company. I like that they are local family business. The only reason I didn't order from them this year is that I had enough seeds left over from my order last year.