I go between Premium Green Maeng Da and Premium Green Maeng Da 2 (always on hand), Green Hulu (has had some very potent batches in the last year or so from my vendor), Gold Bali, and then a fourth one that varies. If there's something new that he has out, I'll try it out, or I'll just pick up a red or something I haven't had in a while. Right now that's Red Bali (it's shit this time around). It is definitely wise to switch it up periodically. However, constantly blending them together (taking a teaspoon of each all the time for instance) has caused me to grow tolerant to it all at once. Don't recommend doing that.