In all fairness the government already KNOWS you have them because you have to register the gun when you purchase it. I haven't gone "gun crazy" yet but I have:
Glock 19 - Awesome all around gun. It is good for carry, good for the home, good for range time, and cheap to repair if you ever need to... It accepts 10, 15, 17, and 33 round magazines and you don't have to clean it at all if you don't want to. I suggest you do it every time you use it of course. My point is they are the AK47 of handguns.
Ruger 10/22 - You have to own one... great for plinking and small game. They are reliable but will fail if you shoot them too much if you use the cheapo 550 round boxes of ammo because it is super dirty.
Savage .17HMR - It is a little beast. I won it in a raffle and had never cared to own one before but after shooting it I had to laugh at just how much power such a tiny bullet has. Don't shoot small game with it lol. It is like the .50BMG to squirrels.
My next purchase is likely a Colt LE6920(civilian M4) or a 1911(brand unknown most likely Colt or Kimber if I go cheap or Wilson/Nighthawk if I go expensive). I may also grab my friends P226 as it is in good condition and his crazy ex put a protective order on him because he threatened to take her to court to see his son lol. He isn't allowed to have a gun for 90 days and may sell it for $350 which is a good deal on a lightly used Sig.
At some point I am considering saving up toward a Mac 10 or Uzi/Mini Uzi. This would be a relatively big deal though as it is a $3,000-7,800 purchase and strictly for fun as you can't really do anything productive with a submachine gun but it would be a blast to shoot haha. A Romanian AK-47 is likely on my list as well but it is toward the bottom as I would prefer an AR-15.
I was looking at the ACR but I have not been impressed with them yet and the price is still unrealistic for what it is. I have seen the gas system fail on the civilian models because bushmaster only included parts that would allow it to shoot low pressure .223 ammo. The fix involved getting parts off the military version and putting them in the gun so it could shoot 5.56. I am not too sure if Bushmaster is including them by default or not yet.
I am sure by now you can see that I am clearly not a "collector" so much as I am a recreational shooter. I buy what I find to be fun.