I have a Dell Inspiron 530 running Linux Mint 1.10 , Ubuntu 12.4 ,Puppy Linux Wary-431-Lupo 528-and Lighthouse Puppy and WinXp in Virtual Box My main business machine, runs great.
Bought this machine for 240.00 including 20 inch LCD from a person losing it in pawn.
Also Dell Dimension 4100 runing Lubuntu 1.04 and Puppy Linux Wary 5 given to me. Runs great
Also Dell Dimension 4500 I paid 20.00 for running Puppy Linux 431 Retro and Lubuntu 11.4 -Runs great! Love the slide in drive setup.
Also Dell Inspiron 531s I just bought at the thrift shop owned by a local church for $2.50 ! It is running LM 13 , Win Vista is installed but I am having trouble with an out of range error I suspect is due to a faulty NVidia driver. It runs great and the price was right!
I have sold more old Dells than I can remember since getting into Linux and have used them myself. The problems I have had with them are few and repairing them and finding drivers is no problem. If only my father had taken a chance and invested $1000.00 to buy 10% of Dell when it was still a home biz and his buddy who knew the founders gave him that chance would have Dell tatooed on my arm :}