"Depends" is the usual and not very useful answer
When we arrived I went through all the prepaid options from the main providers, adding up voicemail costs etc and decided Peoples "IDD Talk" was the best value for me. I wanted something that gave IDD and roaming though, which you might not need. $0.25/min for local and IDD calls. Service seems pretty good, not had any problems (except no coverage at home).
My only complaint is the 3 or 4 texts they send every month in the days before the voicemail service expires (renews automatically). The problem is the messages come in at about 3am - f***ing anoying if you leave your phone on overnight!
Doug.
Prepaid sim card 
