I have a big soft rubbery silicone for my Nexus One, but it's grippy and makes it harder to get in/out of pockets, plus dust and crap sticks to it a little bit.

My fiancee has one of the harder, thinner cases, and it feels nicer, but wouldn't it protect the screen less in a fall? My silicone one has "bumpers" that stick out pretty far on the front perimeter and would seemingly shield the screen in a fall, at least when falling on flat-ish surfaces (a giant spike would obviously still kill the screen, but I don't walk around near giant spikes much).

Another option is those stick-on ones, but they seem like too much hassle for me to bother with.

Another issue is that I'm not really all that clumsy and I've never had a smart phone before a few months ago, so I really don't have any personal data to go on. One time I dropped my Nintendo DS and scraped the shoulder button. That's about it.

Have any of you killed a bunch of phones -- or maybe work in the cell phone industry -- and have racked up a lot of knowledge of what works and what doesn't? Please share!