I can think of one, and only one. Cassie. Everyone is jealous of her, and hates her. Poor chickadee.
Cassie's really the only one of the original Animorphs to make it all the way through to the end relatively intact. If anything she'd be the only character in the series that I
would want to be.
Anyway, if I'm reading the replies correctly, this looks like a "Which 5 characters had it the worst in the series?" question. As for David, I don't feel any sympathy for him at all. He got dealt a crap hand; so did Tobias. One tried to make the most of it (despite all the angst) and the other handled it in honestly the worst way imaginable. He couldn't control what happened to his parents and the target the Animorphs put on his head, but everything beyond that was purely his own doing. I don't know what made him think taking out all the other Animorphs was the best idea (although admittedly he did come rather close). The whole rat nothlit solution was only as horrifying as it was not purely for the idea that somebody was force-trapped into a rat morph, but mostly the fact that the Animorphs would have to live with the guilt of doing that (especially Ax and Rachel), even if they were justified. You're entitled to your opinions of course, I just have trouble imagining David belonging on the top 5 list when you consider characters like Arbron.
But I disagree, somewhat, about pitying the other Animorphs. I mean, try to imagine the kids without the Yeerk Invasion, what kind of lives would they lead? Tobias gained freedom from the war, Rachel loved the thrill of battle, Marco not only got his mother back, but also became a millionaire after the war ended, Ax became a high ranking soldier in the Andalite military, Cassie ended up doing what she always wanted, [...]
Tobias was really the one who profited in some ways after becoming an Animorph; sense of purpose, becoming romantically involved with Rachel (something that wouldn't have lasted very long at all if they never met Elfangor), and eventually meeting his mother. But the others? Sure, Marco did reunite his parents, but even if he didn't, Nora was a sweet woman who legitimately made his father happy and would've done a decent job in his mother's place. Not exactly worth the cost of a lot of things he had to do in the series (planning his own mother's assassination? That took a huge mental toll on him, and let's not forget when he almost got trapped in mid-morph as a roach). Rachel could've found that kind of thrill in other ways (ie extreme sports, workan' fo da poh-leece, counter-terrorism, etc.).
and Jake found purpose in his life--no longer needing to live in his brother's shadow.
...lol ._.