Emma and Cherry.
Emma has legit the best vibes (and booty).
Sad that she's a filthy homeless commie but that's just a detail in the grand scheme of things.
Best LI for Ian: Holly, Lena and Alison, honorably mentioned Cherry and a Gillian recognising she made a big mistake.
Holly, no matter her version, clearly likes Ian for being himself, shares his passion for writing, even wild Holly is a rather sweet, nice and intelligent young woman. Very good fit.
Lena depends on how we play her, can be a great match for Ian, a really good friend or just a fuckbuddy. As said, depends on the playstyle.
Alison, like Holly, is one of the few LIs liking Ian for being himself. Both had school crushes on each other, but never acted on it. Goes to Jeremy only if Ian does not see her visibly swung fence post with "I wanna be with you in a relationship" on it and even if she is with Jeremy, one move by Ian and Jeremy is history.(Unless Ian and her like threesomes)
Cherry seems to be a good LI, but as a side character is rarely seen.
Gillian and a reconciliation has to be seen in future chapters if an option, but what we saw so far hints strongly towards Gillian being aware having made a big mistake with leaving Ian.
Worst LI for Ian: Louise, Cindy, Emma
Louise has extreme character issues, Stan in comparison is an angel as a flat sharer. Needs therapy, her mental stuff is so severe.
Emma and Perry deserve each other, Ian is simply a "fuckbuddy plus" for her. It is very clear Ian is just a substitute. Something that taints her unrepairable for me is, I know some activists in her mold and can only say: No, thank you!
Cindy mainly popular due to her looks, is/was Wade´s girlfriend. Is high maintainance and would prefer Wade if he get´s his groove back.