I have two series that's meant to test how likeable a character can be with different personalities:
World At Strife was written with a young, cheerful, and funny try-hard of a person as the main character. Bit more of a traditional "boy on an adventure" story but with some subtle changes like the fact that he's pansexual, in his early twenties, and has no ambition whatsoever other than to find out who he is.
Scumbag Heroes (ironically a perquel to World At Strife), however has a complete asshole for a main character. Has somewhat the same cheerful demeanor as his successor but is completely aware of his wrongdoings and doesn't care unless it affects him directly. He's meant to be a mix between Travis Touchdown from No More Heroes and Handsome Jack from Borderlands: a fight-loving egotistical prick with a heart of gold.
I honestly love writing Scumbag Heroes' main character more because there's more freedom with his personality.