I've always liked wide angle lenses. I've been playing with one and taking pictures around campus which turns out to be great fun. Places, like the area outside the Student's Union, suddenly look different and strange, and you can get some really interesting angles that you can't get any other way.
If you are interested (and why should you be) the lens I've been playing with is an 8mm focal length FishEye from Samyang. For such a bespoke piece of optics the price is very good, particularly if you get the cheaper silver one. The lens is completely manual, you have to set the focus and aperture by hand, but I rather like that and the cleverness in the camera seems to take this in its stride. The results are pin sharp in the centre of the frame and very good around the edges, particularly if you stop down to F8 or so. The colour rendition is good too, with hardly any fringing.
I'll certainly be taking it on my travels from now on, it gives a very refreshing angle of view to familiar scenes so it should do amazing things with unfamiliar ones.