S&W 586 "Dirty Harry", 10 shots as fast as you can pull the trigger in double action mode, coincidentally I've got a nice one for sale . No wasted gas on blowback and accurate.
Too pricey ? How about an £80 Crosman 357 / Vigilante ? Lots of fun per £. Don't discount revolvers !
If you want auto blowback, the KWC 1911 in its various guises puts a smile on everyone's face, the major advantage of these guns for me is that the CO2 mechanism is in the magazine, so if it breaks get a new mag not a new gun ! Baby Makarov, seen one not fired it supposed to be good too.