I suggest looking at the Marshalls Catalogue. They have a great explanation about suitability of tiles for certain areas. They have a big range. I would also visit places like the London Tile Company which set out the tiles and are really helpful.
We were looking for easy maintenance and were going to choose Indian Sandstone. We were advised against it for our situation and when we say it in situ we could see the problems. This is what we chose. It is excellent, easy to maintain and non-slip.
Yeah, there are so many options now, it honestly depends what look you want and what your budget is!
Porcelanosa do a large range of tiles where you can get outdoor/indoor versions, so that you can run what looks like the same flooring from your interior into your garden. (In fact, the finish is subtly different on each).
Alternatively, there are various kinds of natural stone you can use.