My girlfriend is on GiffGaff's £10 monthly tariff but wanted a new phone after I got my Galaxy S2. She didn't want a 24 month deal or to spend too much.
Looking around at 12 month contracts most require that you spend a large monthly amount or pay a large fee upfront. The £20 contract from Talktalk seemed the best a couple of months ago when it included a HTC Wildfire so I was hoping they now included the Wildfire S but got one better (IMO).
The Galaxy Ace is a decent speed Android experience with an 800Mhz Processor. This is a significant step up from the 600Mhz Wildfire S. Like the Wildfire S it has a half decent 320x480 screen resolution, 5MP Camera, etc.
The cheapest I can find the phone for PAYG is £200 and that is Sim locked to Orange. Talkmobile tend to send Sim unlocked ones which would add a further £20. If you get the £60 Quidco (I always seem to) then you are saving £20+ to get 12 months interest free credit and a usable tariff of the back of the Vodafone network.:
200 any net mins
Reviewed as 4* based on approx £300 PAYG less than 2 months ago here:http://reviews.cnet.co.uk/mobile-phones/samsung-galaxy-ace-review-50002651/