Newer than what?
I would certainly not like to be limited to three revolvers, but I'll give you the top three. However, for reasons which will be evident, I consider six to be the rock-bottom minimum, and that's revolvers. I'd add a Browning HP and a Series 80 Colt (or a ParaOrd) to that, although an excuse could be made for having just one auto.
1. A Model 42, because it can be carried in some pockets that larger revolvers won't fit into. If you don't reliably use the grip safety, a 37 with a bobbed hammer is better, possibly even with a square butt. Any of these guns will also carry well in a Renegade ankle holster.
2. A 2" Model 15, because mine is VERY accurate and fast with Rogers/Safariland grips, and is very easy to conceal. A 2" Model 12 or 10 is also a strong possibility, but I find the sights on my 15 to be a bit faster, and they have never worn on my cover garment, whether "shoot-me" vest or sport jacket.
3. A real gun (although the M15 is close with the "FBI" load). If you ever go where may be bear, a 3" or 4" .44 Magnum, whatever will conceal. If not, a .45 ACP (/.45 AR) of the same size.
4. A good .22 revolver. Although you may prefer an auto, which is certainly OK, you should have a revolver, also, if for nothing but instructional purposes.
5. See 2. You should probably have a steel gun and an aluminum gun, both, unless you shoot the aluminum one just as well as the steel.
6. See 3. You should probably have both.
Some people may feel that a .357 is suitable for 3, above, or even also 2. I have no real argument with them, but at present I like my choices better.
The autoloader is for when you are afraid that the Chinese hordes may overrun your position, and you can't get to your EBR.