"does* this sentence sound* like it comes from a mob"... No, not really. It's informal speech -- colloquial speech -- people use when talking to each other. But, it can also sound like mob-speech. It depends on the context. If a mob boss were in a jewelry store with his gang and he were to say, "alright, boys, grab anything that makes you happy," then that'd definitely would sound like a mob boss, haha. I guess, "grab anything that makes you happy," would sound fine in a buffet at a restaurant. Anyway, sometimes it depends on the context of the situation.

The keyword here is "grab". You grab with your hands, so there's a physical image. Other synonyms like "take" or "acquire" don't have that physical image. It's a very simple-sounding sentence... and mobsters were renowned for being simple minded. No offence. ;)

i think it was more sounds like mob.this sentence can be heard in some gangster movie, cowboy...

i agree with deep blue but i also have to add on that it has even more meanings

This sentence is dual meaning: If its for one's own self, its not like a mob, rather its inspirational in a sense. But if spoken to someone else, it is of course like mob, because you cannot grab whatever you want only at your own will.