Honestly though, it was the best one. Saints Row IV got boring once you had all the powers and you were pretty much invincible. I never played the second SR so I can't criticise that, but the first one was alright. No Professor Genki's magically appearing in it ): I never finished Gat out of Hell because it was lame when I started playing it. It didn't appeal to me like SR3 did, never kept my interest. I also missed the creativity of making your own character.
If there is a new game, I want more challenges involving Professor Genki, hands down. But I don't think there will be a new game to be honest.
Strangely, you were more invincible in the 3rd game, as you could actually upgrade yourself to being immune to all damage, something you couldn't do in the 4th one. Again, strange since in the 4th you were basically in the Matrix, so should have been able to become invincible. But, yea, while I loved the 4th and GOOH, I want something closer to the 3rd, including being able to pay a shit ton of money to become invincible.