Actually, it's not about size as such for me; it's more that I like watching fish interacting with each other. Preferably in something that looks like a semi-natural landscape. And from that point of view, a group of tiny shellies can offer quite as much scope as a school of tank busters.
As for being impressed, some of the more sensitive tiny fish can require just as much work and knowhow as the big ones. Afraid money just fails to impress me. But a nice tank of well kept fish, with enough room for either schools or territories depending on the fish, planned according to the needs of the respective species, that always draws my attention.
I prefer seeing myself as a watcher of a slice of nature rather than a pet keeper- I suppose that's why the community/mixed sizes gets my vote.
(or a combo of both)
(hehe, sorry to the people who like small fish) I feel like tank space is being wasted. I like looking at large fish that to the point where if I fell asleep for a nap and woke up looking at it, it would startle me. Thats the kinda fish that I like; where I'm glad it's in the tank cause if it was able to run around on the floor, it might chew one of my toes off. But, then again, I might just be a little distrubed 
) so it's like a pride thing. But, I do agree a planted tank that looks like a pic of a bottom of a river or something is amazing. I just like big fish is all.
