Uh, chuck norris has never been a nerd thing. A retard thing maybe, but nerds don't look up to chuck norris, we wait and plot his demise.
Nerds have their own 'thing'. It's called being antisocial and being smarter than everyone else around them. Also we don't hate ourselves outwardly, so smart emo kids don't fit into this category. Social people who are smart generally burn out young and are generally freaks of nature.
Let's break you a little bit:
Dinosaurs: Why bother? Raptors have been part of our culture ever since the godless killing machines were first shown in Jurassic park.
Mutants: Aside from the fact that most nerds read comic books at least for some period of their lives, why should we make this our thing? Evolution has ensured that our small genetic superiority is LESS likely to be passed on to the next generation.
Samarai: Ninjas are far more glamourized than their actual historical counterparts were. Samarai are always as they were shown: loyal unto death to their lord. If we are idolizing these guys we might as well idolize crusaders, knights or navy seals. Whatever.
Scots: Ooooo, I wanna be HILLFOLK! Seriously, dwarves are way cooler.
Gladiators: A slave forced to fight for the amusement of the common folk over and over until he dies... while it may be morbidly similar to our careers later in life... no!
Alan Cumming: No man deserves our respect, with the possible exception of Sean Connery.
luchadors: what were you THINKING?
Let's break down some more ideas
Djinni: these guys are awesome, but may be terrorists in disguise.
Jenova: sephiroth is coming to force you to become one with his mom...
Shiva: Who doesn't want to have multiple arms? See mutants.
Vikings: pirates wearing fur and not really after gold, but women and fighting, but pirates the same.
Thor: He's got a hammer! Rather have a dwarf.
I'm not even gonna go into the various fictional book characters we could choose to be our next big thing, since reading is another nerd 'thing'.