There's probably something really obvious I'm forgetting, but I feel confident about the top two. Only thing I'm not sure of is whether EO 5 or Nexus is better, but I gave the edge to 5 for trying to be unique and making me feel nostalgic for EO1 in a totally new setting, where Nexus was more of like... trying to force nostalgia by including stuff from all previous games, but missing a few of the things that I would have really wanted (and putting more emphasis on 3-4 than I would have liked)
There might be a series that I like overall more than Phantasy Star, but nothing else came to mind after thinking about it "really hard" for 45 seconds.