Spigen for sure; I've run the Ultra Hybrid model on the last 3 or 4 iPhones. They have some thinner models that will likely work better for you if your main goal is thin.

Equally as annoying as 'sticky', I'd avoid anything with clear sides as well. Those feel 'plasticky' and have a weird tactile feel as it relates to volume, etc. buttons on the sides of the phone. As mentioned above, it's a difference in material that creates these differences for sure.

For the reasons above, that's why I tend to stay away from 2 piece covers (soft molded cover w/ a hard snap over back) as well.