I'm a fan of Crayola and their Washable's have never let me down yet.
We started off with Crayola Pip-Squeaks - Mini Markers (14 Pack)
for my daughter who learnt to write her name using them.
Now she is out of the toddler stage, we've moved onto Supertips.
Wonderful bright colours; they last a fair while if the lids are replaced after use. The lids don't fall off easily either which happens to be a pet hate of mine!
My daughter loves them and they are truly washable. I've found marks on walls, doors, desks, skin! and plenty on clothes, carpets and even duvet covers - all of which I am happy to say have come out in the wash.
I don't even think of buying any other brand while my family is still young. Supertips are super-priced too.