Treo Pro was in my pocket before the iPhone4. All time favorite was the Treo 650. That phone was a tank. No case, no screen protector, carried in my pocket and still works to this day. But it's like me, old and slow.
Before (somewhat reluctantly [!]) buying the original iPhone [16 GB flavor]), I used the handsome (but extremely tedious-to-use) Samsung UpStage, which I still own, but obviously no longer use. Here are my pics of it, and a link to a YouTube video which hopefully illustrates the reason it is so tedious to use. This gadget was a birthday gift from my best friend at the time, so I tried to act like I really liked it around the guy.
I need to stress one thing the guy on the YouTube video has mentioned but didn't dwell enough on. That damn gadget DEMANDED to be flipped over WAY too much because it seemed everything you wanted to do was always something you could only do using the screen on the flip side. I was ready to, um, flip.
I had an LG Rumor. Not a good phone, but better than the LG Chocolate that I had before that. I finally learned my lesson and steered clear of LG. I will be an iPhone user for as long as Apple makes them!
I actually liked the BlackBerry OS, but their failure to stay relevant with their OS updates, and the dearth of apps made the choice for me. I didn't think so at the time I switched, but I've not looked back nor have I regretted the decision. Especially when one stops to consider just how moribund the BlackBerry platform is.
Mine was the Samsung Messager w/CricKet, before I got my 3GS. it was an okay phone, I was a rapid texter w/these buttons. Also the text messaging was fun on this phone, when my texts would make it through (it would reject them on my end constantly lol)
I had the LG Shine before I got my first iPhone (the 3G and then the iPhone 4 after that). When I switched to Verizon in early 2011, I got the HTC Thunderbolt but quickly switched back to the iPhone. Can't imagine having anything else!