I really like switching between a M1907 SL Sweeper and a Mondragon.
I'm not very leveled up though, so I'm not sure if there are better options.
Played the Rigotti, Selbstlader1916 (both factory), M1907 Sweeper and the Mondragon Storm so far.
Like the Mondragon best so far, followed by the M1907, though the Rigotti is fun if you want to challenge yourself in TDM (or rather: play the "can I hide and reload for 7 seconds before the next guy comes" game after one full auto kill).
Selbstlader is overrated IMO, the very long time it takes for your aim to reset after a shot (your semi auto fire rate means nothing if you can't before waiting for the reset) and miserable hip fire performance (which you need if you storm a flag) is not worth the overkill ammo capacity, 10 shots is plenty enough for the Mondragon and that thing still reloads fast, fires laser beams and deals the same damage... and has good hipfire in a pitch. M1907 is the best option for permanent close combat, Rigotti is IMO the better choice if you primarily fight close but also sometimes end up in medium range fight... if you can make the ammo capacity combined with the slow as molasses reload.
Can't wait to try the scoped version of the Mondragon.