Animorphs/The Pendragon Series by DJ MacHale.
Jake...well, this one's kind of obvious. Jake and Bobby Pendragon are both the leading characters in their respective series. Bobby's definitely more immature than Jake at the start, but that's probably because Bobby has a mentor figure to help guide him for a little while and Jake has no one. When Bobby loses his mentor, his "Uncle" Press-killed by Saint Dane, the main antagonist-it's comparable to when Jake realizes that Tom is a controller; it gives them both motivation to continue their respective fights. Although this happens for Jake in the first book, it happens for Bobby at the end of the second book...after you've already read 600 pages of his incessant complaining. Whew.
Both of them have a responsibility to essentially save the world--although considering the battle on Earth in Animorphs is a turning point in the war against the Yeerks, Jake probably has the responsibility of saving the freedom of who knows how many sentient species. Sounds difficult enough, but Bobby actually has it a little worse--he has to save Halla, which is "everything that ever was, ever is, and ever will be." Both are reluctant leaders, Bobby quits the fight at one point because he is simply tired of making decisions and being a leader for reasons he doesn't understand. In the end, though, Jake comes out of his war much, much, much more damaged than Bobby does. Especially when you take into account the fact that Bobby, at the end of the war, is allowed to go back in time to before he became a Traveler (that's what he is, like Jake is an Animorph), and relive his life with no war, nor any memory of it. And we all know what happened to Jake.
Rachel--In the Pendragon series, there is a multitude of strong, ****y, female characters, but a lot of them only have minor roles (Wu Yenza, Jinx, etc). In terms of main characters...I would say Rachel is an incomplete cross between Courtney Chetwynde, Bobby's beautiful, athletic, outgoing, popular love interest back home, and Loor, Bobby's alien, warrior, beautiful, brave, fellow Traveler, love interest. Thing is, Courtney's annoying as hell sometimes, and Loor's too well trained of a warrior to be as emotional as Rachel is. And neither of them account for Rachel's at-times psychotic behavior, which is really important to her overall character. Actually, the best representation of crazy outbursts of extreme violence only come from the villain, Saint Dane, and even then, they're very out of character.
Tobias--My mind jumps to Mark Dimond, Bobby's non-Traveler best friend back home, who's socially isolated, but not because his family is broken, but just because he's kind of a nerd outcast. Later on, he suffers great emotional trauma and it can be argued that he never really recovers from it. Mark has a special relationship with Courtney (Rachel), but as of now, I'm not sure who really encompasses Tobias's feelings of isolation, his poetic narration, or general angst (although I guess Bobby can angst a lot).
Cassie--This is difficult. It's been a while since I read Pendragon, but if my memory serves me correctly, there aren't many Cassie-esque moral dilemmas. There are a lot of decisions to be made and the morality behind those decisions comes into play, but...it's not like Cassie's moral pandering. I'm going to say Cassie is most like Osa, the serene, wise, but also athletic warrior from another land. Oh yeah, she's also black. But...Osa dies in the first book and only has about 15 lines in the entire series. So I'm really inferring a lot about her personality from her brief appearance. Who knows, maybe she's the missing crazed nutjob that we need to represent Rachel fully?
Marco--Marco's role as the funny guy is best showed through the character of Vo Spader, a humorous fan favorite. He also has a father he lost to the enemy, much like Marco and his mom. The similarities stop there, though, because Spader is dangerously overemotional and impulsive, nearly costing Bobby and the others various missions. (Side note, Spader does actually act a lot like Cassie when he refuses to let a plane filled with people blow up--though he's been told by Bobby that if the plane does not blow up, chaos will ensue. After Bobby narrowly stops Spader, he tells him to go home until he's emotional ready to be a Traveler. Oh, how I wish someone told Cassie that once in a while.) Anyway, Marco's more strategic, analytical half can be seen in a couple other characters, but most interestingly, Saint Dane. Remember, he's the bad guy. Saint Dane isn't usually outrightly evil, but he implants himself in a precarious environment or social situation and does all he can to make sure the people of a land push their land into chaos--but he very rarely actually pulls the trigger. This all requires serious forethought, planning, and strategy, all of which Marco excell at. (Other side note, it also requires lots of manipulation and an understanding of people's emotions and how they will react in various situations. Sound familiar? Cassie...?)
Ax-I feel like I've written too much that no one's going to read, so I'm just going to say Ax is Aja, a brilliant computer nerd, and stop there. Not a very in depth or terribly accurate analysis, but it works.
David--Strongly similar to Nevva Winter. Her ordinary life is interrupted when she finds out she's a Traveler. She sees a lot of different worlds after spending time with the Travelers, discovers she doesn't like what the Travelers stand for, and joins Saint Dane. Dundundun!
Visser Three and Saint Dane are NOT very similar at all, as I alluded to above. Personally, I prefer Saint Dane as a villain.
This was fun to think about. Probably makes no sense if you've never read the Pendragon books before...well, if you haven't, you should, haha.
