Probably the best value-for-your-money body wash I've ever used is Softsoap for men:

I swear the one bottle lasted me 8 months or so. The stuff lathers really well with one of these

When that ran out I tried the Old Spice 2 in one shit they're offering now. I'm 1/4 of the way through the bottle, and I haven't been using it long at all.