Well, since you did it, I’d guess it’s only fair.
1) Remington 870 / Mossberg 500: The Mossberg has a removable choke tube, while the Remington doesn’t. If you get a “sporting” version, you get the dimples that Remington puts in there so you can’t easily install a magazine extension. They serve no purpose from what I or anybody else can tell other than to keep the gun from being “scary.” In any case, this is well-known.
2) Glock 17: It’s nearly indestructible, and it fires the ubiquitous 9mm round. They’re also pretty accurate. +P is available for greater stopping power. Portability is also a concern.
3) Mini-14: It shoots readily available 5.56/.223 ammunition and, barring a major malfunction, goes bang every time. It’s not as accurate as an AR-15, though they have made significant strides recently.
4) Ruger M77 Hawkeye, .308: It’s cheaper than a comparable Remington 700 BDL and just as accurate.
5) Remington 597: This rifle is, in my opinion, much better than the Ruger 10/22. The 597 has the heft and feel of a much larger rifle. In other words, it doesn’t feel like a toy. It’s very accurate, and the magazines are much easier to load and release. It’s also cheaper than the 10/22.
6) DPMS LR-308: It’s an extremely accurate semi-automatic AR-10 that shoots the same ammunition as the aforementioned Hawkeye. Once the barrel is broken in, it can be cleaned quickly and easily. Depending on the length of the barrel, it’s accurate from 600 yards and out.
The next four I’d have to think about.
The Rem 870 Magnum Express does have the removable choke!