I've got to the stage where I almost consider my G36c to be my weapon of third-to-last resort as opposed to my pistols, which I love dearly.
That said, I own two TM Hi-Capa 5.1s, two WA Prokiller 2000Fs and a WA Para-Ordnance HRT Special and I love all of them. Especially and particularly the HRT Special, as it's the first airsoft gun I ever bought and still my favourite. The Prokillers are a close joint second- dual-wielding FTW!
My weapon of second-to-last resort is my TM CZ-75 springer, and my weapon of last resort is my hand, though I'm going to buy a LARP knife and a rubber chicken as soon as I've figured out where to get them from.
My backup is the ACES- a team of people who are just about as crazy as I am!