any reccomendations for 5.56/.223 rifle

Alright, I tried searching so I apologize if this is a double post,

But I was wondering if there is any one on here who owns or has used (frequently) more than one brand of rifle/model of rifle which utilizes the 5.56/.223 rounds. And can provide input on their preferences and why they prefer that rifle.

bonus points if it accepts the same mags as the AR-15.

I'm partial to sig, and S&W.


thanks

PS: not interested in hearing about AK/AK variants or any thing of the sort unless its chambered 5.56/.223
PPS: I have settled on a S&W 915 as a side arm, because its almost identical to my dads service pistol which I enjoyed shooting and has been reliable for him if you have critique on this one as well please speak up.