Gah, I love this show and can't wait until it comes back next season. From what I know of INTJs and ISFPs (which, admittedly, isn't a whole lot), I'd agree that Walter and Jesse fall under these categorizations.
...Plus, I just think Bryan Cranston's kinda hott, but that's just me. ...Sorry. Doesn't really have anything to do with the thread. Hehe.