arrowanas are really neat, they get rather large also. the species really make a difference though. the silver arrowanas from the amazon can get up to 3' in the aquarium, and the asian types can reach up to 2'. thats what you are paying for. also, they come in very different colors.
http://www.geocities.com/Heartland/Plains/9665/buddy.html there's a good website to see some pictures. i can surf around on there for a while sometimes. 8)