I've only played S02 and SO: Til the End of Time (which I believe is SO3).

I actually really loved the characters and plot of SO2. Maybe it's because I played it when I was really young and there's some nostalgia value, but I felt like there were less annoying characters and better plotline and settings than in SO3. I'm a huge fan of SO2.

When I played SO3, though, I wanted to kill half the characters. Especially Peppita! I missed it when the voice acting was ONLY in battles. I really think they were trying way too hard to have some sort of movie thing going on.

Anyway, now I want to go replay SO2.... and never play SO3 ever again.