I picked up the Spigen SGP Steinheil Dual for the same reasons. I actually only use the back protector but it's great. Although, while I haven't had issues with my phone slipping off tables, I don't think I can really attribute that to the protector. I find I can still slide my phone across surfaces as if it were a hockey puck on ice.

http://www.spigen.com/brands/google/google-nexus-4-screen-pr...