There's really only Harmonia/Harmonious Bumblebee, and then IHO. I mean yeah there's Bumblebee and a couple other Froyo ROMs but they're not being developed anymore. I like Harmonia for the stock froyo experience. IHO has a ton of settings you can customize (because of CM7) and I've found for me, that it's almost overwhelming haha but I'm slowly working my way up to it.
I'd go with IHO now since everything has basically been smoothed out, I don't think it can get much better until we get ICS on our phones lol
However froyo works too, so I wouldn't completely discredit it either. But I do agree with watskyhotsky, unless you're used to froyo (which you're on IHO so you're more than likely used to GB lol) you'd feel like it was a downgrade.