Can vouch for Toshiba, my old PentiumII has never missed a beat and is still used for less demanding apps.
Just for interest sake, my old Compaq 486 has also never missed a beat in 15 years, and is still in use almost daily for CNC, but Compaq is now HP and probably different build quality.
I keep them because they have both serial and parallel ports(handy for CNC)
Acer 1.6GHz has had no major issues except for a CMOS battery replacement that took 2 months to get returned. ($2 battery and 30min job that I would have done myself if it weren't under warranty (Harvey Norman))
For slightly more modern machines(!
) Dell seem to have a very strong following in these forums.