I've bought 6 cases so far:

• LG V20 Case,APLUS [Shock Absorption] Drop Protection Hybrid Dual Layer Armor Defender Protective Case Cover & [ Free 9H Tempered Glass Screen Protector] for LG V20 (Black) RETURNED, felt very cheap and slippery

• LG V20 Case, POETIC Revolution Series [Premium Rugged][Shock Absorption & Dust Resistant][Heavy Duty] Complete Protection Hybrid Case w/ Built-In Screen Protector for LG V20 (2016) Black CURRENTLY USING but a bit bulky

• LG V20 Case,ANLI(TM) [Shock Absorption] Drop Protection Hybrid Dual Layer Armor Protective Case Cover for LG V20 (2016 Released) Black RETURNED, felt very cheap and slippery

• LG V20 Case, VRS Design [High Pro Shield Series] Brushed Military Grade Protection with Metal Kickstand (Dark Silver) RETURNED, felt very slippery

• Spigen Rugged Armor LG V20 Case with Resilient Shock Absorption and Carbon Fiber Design for LG V20 2016 - Black ON THE WAY

• OBLIQ Flex Pro Case SHOCKPROOF Slim Light TPU Drop Protection Cover for [LG V20] ON THE WAY

the 2 on the way are very thin and just hard rubber, I wouldn't use them until I get a good screen protector...