I think the most beautiful renditions of the Meru mountain are not to be found in India, but in Thailand.
The Buddhist stupa was probably the first architectural construction that was consciously moulded over the concept of the Meru mountain (which is of high symbolic importance in Buddhism). The later Hindu temple architecture in India was undoubtedly influenced by the architectural model of the stupa.
As Buddhism spread to East and South East Asia, people there found several brilliant ways to represent this concept. The pagodas of China, Burma and Japan have evolved out of the stupa. In my opinion, the very best of these representations is the Thai temple. One day, I have to go and visit these places myself :) By the way, the traditional Thai headgear itself looks like a Meru.