I got a 1TB Samsung SSD for just under $500 which I thought was a decent deal. There are cheaper drives out there (e.g. Crucial), but I won't go budget on SSDs again.
One of the cooler changes I made this time around was go liquid cooling on the CPU with the
Corsair h110. It's quieter, system runs cooler, and it just looks cleaner inside. Really happy with it so far.