Remington 870 tactical - this got an "are you f'ing kidding me??" from the nearest pistol lane. He was undoubtedly impressed with the volume of a .12ga fired indoors next to a concrete wall. I was too.
Daniel Defense AR - Two kids walked over to see what I was shooting, their mom comes over to grab them and says "thats a WASTE OF MONEY!!".
I saw a pair of winners at Sherburne last time I was there. They both had "operator" beards, one was wearing a Punisher T shirt, and the had on gun store tacticool shirt. I knew I had winners when they thought my, made like a Swiss watch, K31 was a, made by a drunk Russian, Mosin Nagant. Then they pulled out a flat top AR15 without a front, sight, rear sight, or optic and went to town dumping magazine after magazine on a target 25 meters away.
They had my attention better than anyone has had for a long time on the range.
My Hakim Rifle or P08 Luger seem to get noticed. The Hakim more so only after firing it. The combination of 8mm Mauser and a muzzle brake seem to make people look.
This got a lot of attention. It is scary quiet and i can dump a whole 25rd mag, hiting the steel in rapid succession at 50 yds with it.
This gets big attention, because of the muzzle brake, big boom and swinging plates at 800 yards.
Outside of that, Anything with a Can on it draws attention. especially my .308 700 when i'm shooting .308 subs. It is quieter than my 300AAC ARs, by a lot.