I left my BlackBerry Pearl. It was a great phone. Small, got stuff done. Not too fast but amazing and reliable. Battery pulls every day were something I wasn't happy about though. Especially with having an otterbox.
Cool thing is I have a perfectly mint Blackberry Pearl as a backup.
LG Voyager. Hate the touchscreen that scrolls and keeps scrolling past where you need to go. Then you press to stop it, and get into a contact you don't want.
(I am leaving it, 2 Droids in shipment waiting to hit my house soon)
I left a BB Pearl for the Droid a week ago. While the BB was functional, it really wasn't a good internet data device. Also, the fact that I had it on AT&T didn't help (dropped calls, text messages that wouldn't go through, etc.)