There is no best protein.
Lets say someone is lactose intolerant, they will need an isolate or a vegan protein.
For general consumers they are fine with a normal whey.
This is how I would break it down:
If cost is not an issue:
XF 2.0 (LCP, Cinnamon Roll, Mocha, Chocoalte Mint)
MSI Lean Whey (Lean Charms, Oatmeal Cookie etc...)
Ghost Whey
Beverly UMP (CNC is amazing)
Metabolic Nutrition (PB Cookie is GOAT)
A little costly but not breaking the bank:
MTS (Pumpkin, Red Velvet, PB CnC, CnC, Triple Aussie Biscuit)
Nutrabio
Iforce Protean (Blueberry & RV)
Cost Effective:
Cellucor (Cinn Swirl, Choc PB, Molten Chocolate)
PES (Vanilla, WCM, PB Cookie, SnickerDoodle)
AI Sports Whey (Birthday Cake, Pumpkin, Cinnamon Roll, Mocha)
Animal Whey (Banana, Red Velvet, Cookies & Cream)
Rule 1 (Banana, Fudge Brownie, Red Velvet, Pumpkin)
USP Labs
Isolate:
MAN Sports Iso (All the flavors are great I have tried)
Dymatize Iso-100 (Birthday Cake, Orange Cream, PB, Choc PB)
Allmax Isoflex (Choc PB)
Gaspari Precision (Blueberry, Neo, CTC)
Vegan:
PES Vegan (Choc is best)
AI No Whey (Pumpkin)
SAN Raw Fusion
and I am sure I could add more, but just off the top of my head.