Maybe it's just me, but I've never had a "bad" phone.
At the time, all mine worked well.
My current N96 is laggy, and lacking in the battery department, but I wouldn't class it as a bad phone, it does everything I could ask of it.
Maybe my "worst" phone would be the N73, it was just rather large, but at the time it was awesome!
Same here, there seems to be two schools in the phone world, those that never get a phone problem and those that apparently go through half a dozen of the same phone because it's "rubbish"...
Having said that maybe it's because I make sure I get the phone I want?
Nokia 5210: Yay! Lasted me around 5 years of bouncing before it finally broke. Texted and made calls, also had Snake!
SE T610: First SE phone borrowed from my mum, who was given it by my sister after about 3 years of use. Rubbish camera by todays standards but overall a good phone. It was one of the reasons I went for the..
SE K750: An epic phone, excellent camera, played music and had some good games
SE K800: Well you have to update to the new one! Even better camera and a proper flash, the main annoyance was the lack of LED...
SE K850: Much sexier phone than the K800 and it had a flash. The media player was pretty good too. Just a shame it had a load of rubbish trial games on..
HTC Touch HD: I love it, was a bit slow before I flashed it, ever since it's been excellent.
??: Still trying to decide what to get, amazingly I haven't got bored of the HD yet.
The only time I've ever had to send a phone back was with the K750. I got it at release and it would occasionally reset for no reason. Sent it back a couple of weeks after I got it, reflashed with the newest "rom" and it worked perfectly since.
Moto RAZR v3
Spent more time being fixed than actually being used.
Ah yeah, the V3. The thinnest flip phone, but also the widest...

and the most delicate it would seem, according to my friends...
Touch unsensitive buttons and a stupid d-pad. What were they thinking?!
What do you mean unsensitive? I never had a problem with them (in fact they are the reason I went with a fully touchscreen phone for my next one). They did however start to die about 11 months in, probably because of the massive amount of water the phone ingested in it's life (Used to stick it in a sholder pocket where it would get wet from rain and sweat when I was out. The d-pad was annoying, think it was directly caused by the few issues with the joystick clogging up on the older ones.