Steam. 
I use PCSX2 occasionally, and it's quite alright.
VLC Media Player and MusicBee are also good.
I also use BurnAware occasionally for making audio CDs and mp3 CDs.
Over a year ago, a friend showed me a little loophole on the COMODO internet security site that allowed me to download the premium version for free. Maybe that counts, I don't know. Works pretty nicely, though -- and I use it every time I turn my computer on.
The freeware version of Chaotica (fractal design) was so good, I upgraded. I like creating fractals.