Really depends on what you like and are looking for in terms level of protection but I have a few. I initially bought the Otterbox Defender. It's normally what I get because I need a holster while working. I like the Defender a lot but it makes an already big phone much bigger. I then got the Apple leather case and the Seidio Surface case combo. I got the Seidio mainly for the holster as it works with the Apple case. I also got the Seidio Dilex Pro case combo. Again, I got the Seidio Dilex primarily for the holster as it works perfectly with my Magpul case. Bottom line, the Seidio cases are very nice but I use the Apple case when I want slim and the Magpul when I want added protection. The corresponding Seidio holsters mentioned above work great for these cases.
The Seidio and Best Buy Platinum are identical. I'm pretty sure Seidio makes the Platinum cases for Best Buy. You can get it with or without a kickstand. Seidio also offers one with the logo reveal that is not offered by Best Buy.