We have a Dell Inspiron 1525, running Vista. We bought it new in Sept. 2008. No real complaints about it.
However my daughter's computer (same as ours, given to her as a h.s. graduation gift in June, 2008) is giving her all types of problems. Constantly shutting down, freezing. She just tried putting two songs onto her ipod and the computer caused that to freeze. No idea if it's hardware or software causing the problem -- she's just trying to get it to hang on until she gets done school and can buy something new, probably a Mac. Of course, she has lots and lots of programs on hers and although she's always been careful with it, it has travelled back and forth to school for four years so who knows why it's being weird. These things simply don't last forever . . . .
You can search Dell's website for refurbished computers. They are factory refurbished to new but are cheaper than new.
Wireless is great . . . but our Belkin router literally blew up (smoked poured out of it) after less than 2 years. Went with a Linksys and have had zero problems with it -- easy peasy to install too.
Wireless mouse rocks.