For 2D visualization, t-sne is an excellent tool. I've used it with word2vec and you can see clusters of similar words:

https://raw.github.com/dhammack/Word2VecExample/master/visua...

https://raw.github.com/dhammack/Word2VecExample/master/visua...

https://raw.github.com/dhammack/Word2VecExample/master/visua...

And more in https://github.com/dhammack/Word2VecExample/tree/master/visu...