Hmm I'd like to play as a young character, maybe low teens, but still fairly reliable. The kinda child that reads on this kinda stuff (nerdy I suppose) but is handy. They aren't strong, but they aren't weak. They aren't smart, but aren't dumb. They aren't always friendly, but aren't hostile. Fairly in the middle. But should be caring of others, like Clem

and is adaptive to the situation, a character that can improvise depending on the task at hand, maybe even more so than Lee (so we can make that amputation in time god damnit!) Female or male doesn't matter to me, it'd be interesting either way. I'd say start the character off with a bad note, and have people hate him/her, and kind of baby him/her, and the character will have to go through other experiences and become an even better survivalist, and later be faced with a very difficult problem (a walker horde, an attack from another group, a surrounded situation, etc.) where your character, depending on the ways you handled previous problems and trained yourself, can either go BADASS and prove that you are not a child, but as Chuck had said, you are ALIVE. Maybe at the end go from the follower to one of the primary leaders, using your wit, your newfound strength, your acquired skills, and your ability to improvise and strategize to keep your group alive. I'm not saying have a teenager lead mid-aged adults, but becoming a leader in a sense like Glenn of the show. Not be the central leader, but someone who can step up when needed and take charge and be someone that the group looks up to.
Either that or your character absolutely fails and gets many of your group killed, becoming a liability to the group and maybe a detriment for awhile after. Maybe be able to prove yourself later on, but never be what you would have in the first choice.
Or maybe a third option where you failed in decision making, and preparing yourself for the hardships to come, you aren't able to kill walkers when they attack your friends, are overpowered by a walker and get seperated by the group, and by the end are killed by a horde. Maybe just before sacrifice yourself to allow others to escape survive, seeing that you made it back briefly.
I wouldn't like a Ben character, like seriously by the end I'd hope suicide was an option. But this I think would be pretty cool, and would allow for a branched story. Or if Telltale couldn't do that, have those you save if you are the better version get killed off in unsavable situations (like Ben). Then you'd still have the same arc. Then your character could disappear instead of die. Your fate unknown :P