recommend a 26" XC rim
 

the Alex DH-19s that came with my Monocog are tankish. i am looking for something that is responsibly light and not terribly expensive.

considering the following:

Sun-Ringle Equalizer rims. affordable, light, durable? come in various widths, what's a good width for my 150 pound size and XC style? they come in odd sizes from 21-29mm.

Mavic XM517: mid-priced rim from Mavic. not disc-specific but they sound very nice for a little more than the Equalizers.

Your on PinkBike too. I think I already replied there.

What width tire are you running? If you're on 1.9 to 2.1, ~21mm is fine. If wider than that, get a 25+mm rim.