What's the best finish for bathroom walls?

What's the best finish for bathroom walls?

That all depends on your personal taste.

Is there tile on the walls?
Wallpaper?
Or just painted?

Normally most people go with a semi-gloss in a bathroom, for light reflection and ease of cleaning. But if you have glossy tile, you might want to go with a flat latex to give a little contrast to the gloss of the tile.

Either way, you'll want to keep in mind the moisture factor.
When you buy the paint, be sure to tell the clerk at the store where you're using the paint. Todays bathroom paint usually has some additives to guard against mold and mildew.

For tile, you'll want to seal your tile at least once a year.
Some bathroom cleaners can strip the sealer off your tile over time, so you'll want to protect it.

For wallpaper, you might want to look into a vinyl based paper to help with mold and mildew prevention.

Do Paint with a Border.
Its easy and it looks nice
=]

Actually for ease of cleaning I'd go with tile floor to ceiling. You can do different patterns but it makes for really easy clean up, with a good grout, moisture is not a problem. Hope this helps

my parnter is a painter and decorator and he suggested egg-shell paint.

paint is okay, but moisture, mold, or mildew will eventually become a problem. In South Korea they also put a drain in the middle of floor so that the entire bathroom could act as a shower, making the bathroom REALLY easy to clean. Soap scum is a problem with paint too depending on where there is paint and where there is tile.

Actually... paint is a suitable surface for bathroom walls, without worry of mold or mildew, or moisture damage. You just have to get the right paint.

You want to make sure that you're using a 100% acrylic interior house paint. You want to use a premium quality paint. You want to use a paint with a moderate to high sheen.

If you use a premium quality paint (Valspar at Lowe's, Behr at Home Depot... don't use Sherwin Williams, way too expensive for what you get...) it will contain in it a mildewcide to prevent the growth of mold and mildew.

You need a moderate to high sheen (satin or semi-gloss) paint because low sheen paints, like flat and eggshell, are somewhat porous, owing to their nature. Over time, humidity in bathrooms can penetrate through flat paint and cause damage to the substrate.

You should also put two coats on.

All in all, I'd definitely go with a painted finish. Easiest to work with, cheapest in the long run, and plenty durable, if you're smart about it.