I'm a big fan of sleeping masks.
Partly because I'm lazy and like to see results when I wake up and partly because it is just too hot to comfortably do a mask in the summer in Vegas. The times I've tried to do a mask or even a pore strip, it's ended in a sweaty, damp mess.
Boscia's Tsubaki Deep Hydration Sleeping Mask is my favorite because it's super hydrating but not crazy heavy. A little bit goes a long way and it doesn't make me break out at all. I wake up with a really nice soft texture to my skin. Skincare and cosmetics are probably my biggest splurges and even then I find great deals online and with the occasional Sephora discounts (I usually buy one item at a time whenever they do their big sample bags).