Wow! Site redesign! This is definitely a good sign =)
I have hop ein a new update once again!
I really love this FE, so easy and does anything you could probably want
I would say that the top two are definitely Maximus Arcade and Hyper Spin, but Maximus does have support fo more systems. If Maximus updated it's theme to have system specific themes (like Hyper Spin) instead of having them all on an arcade system.