This Side of Paradise

Definitely not as good as Gatsby, but that's a forgone conclusion. There are a lot interesting scenes, ideas, sections of poetic prose, and characters, but the narrative is so loose - one of the typical flaws of Blidungsroman novels. For example, he starts talking about socialism and the poor near the end of the novel - almost entirely out of nowhere. I mean there has not been a single thing really to show that that's something the character cares about or mistakes or wonders about really at all. And it's a fine conclusion for him to start caring about the less fortunate, but then the novel ends without him doing anything about it. (Also when it is written prevents him recognizing the pattern of fallen ideals and heroes that would repeat itself in the USSR.)

There's also a whole chapter in the form of a play - which is fine but seems like a pointless experiment - and tons of poetry - most of it mediocre.

Basically, if you are interested in that sort of prep school to ivy league track or the age of flappers and prohibition or when a character has a series of relationships with different types of partners and learns a bit from each one even though they fail - then you will find something to like. And you will be able to see an author's first novel show signs of promise. But otherwise, I'd say it's just fine. There's a lot better stuff out there, including by Fitzgerald.