This one felt a bit ridiculous to do. I know that Amsterdam attracts so many tourists a year because they rather pragmatically decriminalised the marijuana trade, but I didn't realise how much more Amsterdam had to offer.
Still, we went into the coffee houses and tried some of the many weed varieties have they have available. It's an odd thing, but most of these places are pretty tacky.
There wasn't an easy way to find nice places really, we kind of stumbled across some. You'll find that all coffee houses have a green and white flag/sticker in the window. If you can't spot the sticker, usually they'll have a big Coffee Shop sign (a Cafe or Coffee House sell coffee, and only coffee). Also, coffee shops can't sell weed and alcohol, so if you see alcohol signs, that's not a coffee shop.
So yes, #90. Done.