I quite fancy giving these a try after reading some recommendations on here. A check of eBay shows 4 main brands:

Americolor
Sugarflair
Wilton
Classikool (looks a bit homemade!)

Has anyone tried any of these brands and would you recommend one in particular? Are there any particular colours that work better than others (I see in the feedback for the grey colour that there's a green tinge to it - though there was only one mention of it so it may have just been a dodgy bottle (or user!)).

i have used wilton and sugarflair, i still use both but mostly sugarflair.I just think there is more variety of colours and they have just brought out a few more new ones. But wilton are still equally as good in my opinion. Each colour gives you so many different colours by adding more or less to give you different shades.

I plan on registering with my council this year to sell cakes to the public from home, if i do this i know i would not legaly be aloud to use americolour as i belive it is on the list of stuff not to use from the Food Standard Agency (i think thats what its called)

Good to know about the standards thing, thank you. So I think it's between the Wilton and the Sugarflair and given the range and that the Sugarflair is slightly cheaper I think it might be the winner - unless Wilton is slightly better?

i like sugarflair

I used to work in a store that sold cookware and cake decorating stuff - the "serious" cakey people used to swear by Sugarflair. I've been using them too and find that you don't need a lot to get a good solid colour.

I have seen some neon gels sold in our local Tesco though that I fancy trying out.