I've tried lots of different chai blends, and enjoyed them all. I think it is much more fun to make your own and experiment, but I've always been a kitchen adventurer. There are so many variations... I love crushed red pepper flakes or black peppercorns, as I like a bit of hot kick... and I love coconut and lemongrass, as found in Adagio's Thai Chai blend.
I noticed someone commenting on the expense of vanilla beans, and wanted to interject this piece of info. Williams-Sonoma has a Madagascar Bourbon Vanilla paste
in a jar... not an extract, not even really a liquid, more like a suspension/gel containing the actual vanilla bean. So much easier than dealing with the beans, same amazing vanilla taste, and more economical because the jar will last forever, and you don't have to worry about a partial bean drying out or ruining. The jar is 11.00 USD, but each one lasts me at least 4 to 6 months. It's made by Nielsen-Massey who also markets a liquid extract, whole vanilla beans, and vanilla-infused sugar. I much prefer this paste to extract or dealing with whole beans.