I bought one of Armarkat's largest trees/condos and it's worth every penny I spent.

My cats just love this thing.  It's multi-level, has 2 "rooms" so each cat can curl up in it's own place, as well as 3 high, open, perches.

The instructions to put it together are extremely easy to follow and they even include the 2 tools you need to do it.

The beige color blends well so the largeness of it doesn't smack you in the face when you walk into the room.  And it's VERY sturdy.  I bought it several years ago and my cats climb all over it daily.  Except for vacuuming, it requires no maintenance. ...