Since you mentioned that you like to play tanky champs, perhaps you would like Poppy? She is classified as an assassin and when played right she is downright scary as hell.
Of course, if you want one of the other's mentioned by RA, a just something to note about Talon: he ooms, really hard if you're not careful. Ever since his nerfs a while back, he has had a somewhat troublesome mana issue. Yes, as I'm sure someone would point out, it was put in place to keep his W in check since it was very spamable. But, the extra cost they added on to it along with the mana regen reduction has made it so that in order to keep up harass ou would need to build a philo stone. This however hurts his damage alot early game, which is bad for assassins, especially talon. So to counteract this mana need, you gotta get mana regen runes and take the place of your armor which is really risky since you're so squishy to begin with.
TLR: IF YOU GET TALON, GET READY TO OOM AND NEED MANA RUNES. SO GET KENNEN INSTEAD =]