Any of the buck mark series are stone reliable and as accurate as you can shoot. Same goes for the Ruger mk III. I wouldn't exactly call the ruger an entry level pistol, especially the higher end models, same goes for the buck mark. Run, don't walk away from the mosquito...you will not be happy nor will you ever get it to run reliably. The gsg is ok, but the buckmark will be 4x as accurate for 50$ less if you go for the base model, and never give you issues. If you shoot the gsg alolt, it will give you issues. Maybe not big ones, but they are more maintenance intensive for high round counts. After that, going up in price are the cz kadet or sig 22..neither one is as accurate as the buckmark or ruger, but much more so the the gsg, and won't break like the mosquito, and more reliable then both. For my money the CZ is the best one.
Kimber 22's are ok, but really light due to being built on an all alloy frame and slide, but have the benifit of working in your 1911 gear if that's what you shoot. Same with the gsg.
Depending on what your competeing in, both the M&P and GSG are not paticularly accurate. For idpa shooting out to 15 yards or so they'd be ok. Any of the other's will shoot the wheels off of them.
edit---just saw price range---for that money, either the ruger or a buckmark mid to high end are going to be really nice shooting pistols. Contruction wise, the mp and gsg are toy like compared to them.