cement based adhesive

[oneotu]

Hi.
As there are that many tile adhesives out there can anyone tell me the best cement based adhesive to fix 600x300mm ceramic tiles onto plasterboard which has not been skimmed, also one which gives good working time? I have heard of Mapei but there are that many types. It is a bathroom by the way
Thanks in advance

[darrenba]

I use this pretty much all the time for wall tiles these days - has a pot life of 3 hours

http://www.tilemasteradhesives.co.uk/standardsetaflex