From what I've heard, Group N is some of the best stuff. It's a stiff rubber bushing. People like those because they don't need to be greased. The other option is a polyurethane bushing, which can come from whiteline, perrin, etc. These are the ones that need to be greased, but I'm pretty sure they are more firm than Group N and usually easier to install. Group N is made by STi and is a step up from STi bushings