FRSO seems good on most things, but supports "upholding past treaties" with native Americans, which is somewhat of a red flag. PSL seems good but I've heard claims that they're not that good on the settler colonial issue either and lack proper democratic centralist structure. I don't know much about the WWP, but their 15 point programm doesn't mention landback at all. I know next to nothing about the other socialist parties/orgs on the US, so I can't give my opinion on them
WWP are good comrades with good principles, but the organization isn't quite there imo. I tried joining as a candidate, found out that their candidate classes were only on a day I was unavailable, and they were like "okay, that's no problem!" Which seems like pretty poor standards to me. Also they kept asking me if I could be a delegate on international trips, on very short notice, despite being a new candidate and not having a passport.
PSL seems to have standards for their members and are trying to form organizational infrastructure in the form Liberation Centers. Definitely strike me as a more serious party.