You may or may not find the tips in this thread useful, but I posted a list of all the apps that I have frozen that have caused me no problems.
Also, for a case, about the only good onse on the market right now are the Seidio Innocase, or the Seidio Innocase Active. I hate to sound like a Seidio rep, but I really have tried pretty much all the cases for this phone.
The hard plastic ones from Verizon are very cheap, very brittle, and very prone to scratching your phone. Oh, and they don't fit right, either.
The soft gel ones from Verizon are better, but they still didn't fit quite right, and they offer pretty much no impact protection, which is WHY I want a case.
The Otterbox was recently released, but almost every review I've read of it has been negative. Build quality is lacking, fit and finish are poor, and there was even a post on this forum this morning about one breaking after a 2ft fall. The advantage that the Otterbox offers over any of the other brands is that it covers all the buttons AND there are rubber plugs for the charging/headphone ports.
The Body Glove is pretty much the king of protection. It's got soft touch felt on the inside, a rigid plastic frame, then rubber on the outside. I've had them on various other phones, and they're pretty much indestructible. The downside is that they're very bulky, and some people find that rubber surface is hard to slide in/out of pockets. I never had that problem, but I also don't wear jeans that are tight enough to show my genitals haha.
The Seidio Innocase is a thin plastic case with soft touch rubber on the outside. The rubber doesn't show marks, doesn't stick in your pocket, but DOES feel good/grippy in your hand. I've had mine on my phone for about 2 months, and it looks perfect. I work construction, so I'm constantly getting stuff on it, scuffing it on things, dropping it, etc. The only issue I have is that 2 days ago, I snapped off one of the mounting tabs. But it wasn't the case's fault. I wasn't paying attention when I took it off, and bent it far past a reasonable angle. It's ok, though, I was planning on buying an Innocase Active next week anyway. Also, the case stays on just fine with the missing tab, it still doesn't wiggle or come off.
Finally, the Innocase Active is (according to reviews, I haven't touched one yet) essentially the same as the Innocase, but slightly thicker, with a rigid skeleton, to improve protection. It also has rubber covers over the power, volume, and camera buttons, but not over the charger/headphone ports. I've been so happy with my Innocase that I'm ordering one of these.
Sidenotes: To use an extended battery with most cases, you have to leave the battery door off. Some cases fit in the car dock, most don't. If that's a factor, make sure you know before you buy. Pretty much every case I listed can be found on amazon or ebay for cheaper than MSRP, so google around before you buy a case. I paid like $21 for my Innocase shipped to my door from ebay.