I would say that starting out a frozen shooter is still one of the best weapons a ranger can have. Running back and forth tagging things for the rest of the party to attack is super helpful.
Kicking it up a notch you can do the same but on a grander scale with the arrest needle/freeze traps (if you have them). I've not tried any of the other higher tier freeze weapons yet but I'll also add that a grave digger with good stats can absolutely decimate a room haha.
Mechwise boondocks saints is my favourite so far. It's a bit more powerful than deagle/mystic spirit and the hell special is great for seabed. Really want to get my hands on an armageddon tho...