SH Wet Cement, aka the most perfect grey that ever existed. Not too light, not too dark, not blue toned, no odd shimmer. It's love. At $3 this love is less expensive than RBL, which I'd have to sell my first born to haul from (again, I'm still recovering from last year). Two coats, and this has a perfect formula.
Also, we have SH Cosmic Blue (they were buy 2 get 1 free, and I wanted Wet Cement and a back up of Purple Pizzazz [their spelling, not mine]). A shimmer blue, not quite a frost, with both bar and round holographic glitter. Unique for sure. If the formula was a little more jelly-ish this would work better, but alas, the last coat covers up previous coat's glitter. Three coats, two left a little bit of balding.