Tango have had the $50 sign up bonus in the past but they took it down and I notice it's back up again on their Home eSelect plan.
Tango are an energy provider (electricity only) that only service Victoria. I'm posting this because they are often the cheapest provider for your average Victorian. They offer easy to follow flat rates, none of this pay on time discount business that many other energy providers do.
Daily supply charge and usage rates will not increase for a minimum of 12 months. $50 credit payable after 60 days on this product from the supply start date. Monthly and electronic billing applies.
I would recommend anyone interested in switching to run a comparison from the https://compare.energy.vic.gov.au government site, ideally download the smart meter data from your power distributor (eg citipower, powercor etc) and use it for an accurate comparison.
Also claim the $50 state government bonus for doing the comparison if you haven't already. https://powersavingbonus.energy.vic.gov.au/
Personally I'm not with Tango as I have solar and export a lot, as such I'm better off on the AGL solar savers plan which pays a higher feed in tarrif, but having done comparisons for family and friends Tango always seems to be the cheapest for most peoples circumstances in my experience.