I've always had the idea that certain weapons were better in zombies than others, but could never 'prove it'. For example, I don't like the HK21, but love the Galil. Or my mate uses the AK74u but I think the MP40 creates more points.
Well, I combined some data from the wiki in a spreadsheet.
Damage:
By waterstraat at 2012-07-23
Above shows damage/second, combining damage, rate-of-fire, reload time etc. Damage is head-shot damage.
And revenue:
By waterstraat at 2012-07-24
This shows the amount of points earned when shooting all the ammo in round 10, minus the costs.
And see, the Galil is 'beter' than the HK21, and the MP40 generates more points than the AK74u
Note: the data isn't very accurate, for example, splash-damage isn't used.
(Edit: revenue-chart was off)