I have a Herman Miller Sayl (http://www.hermanmiller.co.uk/products/seating/performance-work-chairs/sayl-chairs.html http://www.hermanmiller.co.uk/products/seat

I have a Herman Miller Sayl (http://www.hermanmiller.co.uk/products/seating/performance-work-chairs/sayl-chairs.html http://www.hermanmiller.co.uk/products/seating/performance-w...), which is a bit cheaper than an Aeron and also, I think, more comfortable for those who don't like the mesh. They come in fairly cheerful colours - I have a white one with a bright orange seat. I'm not sure they're as ergonomically sound as an Aeron, but I've been very happy with mine for the last five years (I did tear one of the armrests in an office move, but they sent a replacement free of charge).