MP5 and nothing else. SMGs are kinda obsolete for most purposes these days, as such what you chose isn't going to matter much but since it's not going to matter you may well just go for the objective best.

If you're looking for something to just have fun with MACs are there, Uzis are also objectively decent. The Beretta M12 is also good but most importantly it looks nice.

In the end, if you're going to go for an SMG go for something from WW2 because they're cool and that's about when they reached peak relevance.

In any case:

>most modern shit looks like it's simple plastic

If they're SMGs for civs they are for mall ninjas because serious shooters don't buy SMGs. Why would you? They're objectively useless.

SMGs exist for 3rd world police departments and sheer fun factor. Even the spec-ops niggers aren't using SMGs anymore. The AR-15 is The One Rifle to Rule Them All.

>Favorite models

Pics related make my dick hard every time I see them.

>mechanisms

No Blichlock please, it's expensive and doesn't do anything.

>features

Light, tight and good looking. Granted the Thompson ways a lot but that's also why it doesn't shoot like utter garbage. You know…because it's in .45.

>calibers

9mm Parabellum and nothing else.

If I could own any 1 SMG it would be the M1A1 Thompson just because it's pure sex. If I could own 3 it would be the Thompson, Mp40 and Beretta M12(I have an irrational preference, the MP5 is objectively better but that's life for ya!).