Check GRH's DFP Tool which will list all the ISP's in a certain country that at least have IPv6 active in BGP. This tells you that the ISP has at least an IPv6 prefix and also if and how well they are connected to the rest of the world. We don't have a separate FAQ entry listing "native IPv6 colos" as in effect any ISP can do this the moment they turn on BGP and have global connectivity. Plugging in Ethernet is really way too easy and that is all there is too it for them to get it to their customers. As such, the best way to get it is to ask your current provider or the one you would like to host at, if they don't tell them that you are going somewhere else, then check GRH and find one that does. And really, that list is quite long as it is so easy to do, but you of course do have to go somewhere that is actually not skimming on things or reselling as these places don't tend to be have time/money/etc for doing innovative things, the question is of course then also if they can actually provide good hosting to you in the first place. Of course, you can also check the ISPs where the SixXS PoPs are hosted, all (except for the NREN's ;) ) offer native IPv6 hosting possibilities for a long time already.

I don't work for them nor be a client of them, but blacknight.ie are offering IPv6 hosting. An example of a hosted website on IPv6: http://www.menupages.ie/