I have got plastic tiles, black and white.
So it looks good and so far after 2 years, still in good shape.
No curling up or coming off the floor.
I also use a bathroom duck.
Definitely NOT carpet.....I've yet to meet a man who can aim straight down the loo 100% of the time. Think of all the accumulated drops of wee in the carpet, yuk!
carpets in a bathroom are soooooooo unhygienic. when i bought my previous flat and re-did the bathroom i had the unpleasant task of ripping up the old carpet. OMG - that was one of the worst jobs i've ever done. the memory of the stench that came up off the floor, and the stains that were left behind have stayed with me 2 years after the fact!
Depending as to where your bathroom is situated I would go for ceramic tiles , or a really good vinyl flooring , ceramic floors are so easy to keep clean , but things don't bounce on them !!