Corsair CMY8GX3M2A2400C11 Vengeance Pro 8GB 2 x 4GB DDR3 2400MHz C11 Memory Kit 1.65V at Amazon.com
G.Skill Ripjaws X Series 16 GB (2 x 8 GB) 240-Pin SDRAM (PC3-12800) DDR3 1600 CL10-10-10-30 1.50V Dual Channel Desktop Memory Model F3-12800CL10D-16GBXL at Amazon.com
G.Skill 16GB (2 x 8GB) DDR3 PC3-19200 2400MHz TridentX Series CL10 (10-12-12-31) Dual Channel kit (F3-2400C10D-16GTX) at Amazon.com
Amazon.com: OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S32P) : Everything Else
G.Skill 16GB DDR3 PC3-19200 2400MHz Trident X Series CL10 (10-12-12-31) Quad Channel kit at Amazon.com