SR4 is where the series jumped the shark for me. Turning up all the wacky random insanity worked great for SR3 and helped it find a niche to differentiate itself from other GTA-likes, but trying the exact same thing again made it go from parody to farce. It was very obviously trying so hard to top SR3's absurdity, but it just went so insanely overboard with it that I got desensitized to it, and it all came across as just plain stupid.

And on top of that, they give you superhero powers that basically make using cars obsolete... in a GTA-like. The vehicle customization was one of the best systems of SR3, but they actively disincentivized using vehicles altogether in 4.