What kind of coral does it for you? What's in your tank that you're the most proud of, or what's something you've seen in a magazine that you really wish you desired? Do you have lots of it, or just a little?
Me it's SPS. I think it's because it's supposed to be "difficult" and it makes me excited to see SPS doing well in my tank, makes me proud. I also like to bring my face RIGHT up to the glass (like an inch away) and look over all the little polyps. I used to have an interest in macro photography and I think that you're getting 1000 corals for the price of one when getting an SPS colony
I think having a small 45g tank lets me get close enough to enjoy it on that level. I think if I had some big 240g plus tank it'd be a different story.
My colony I'm the most proud of is the pink pocillopora I picked up bleached from an LFS and that I've been nursing back to health slowly. It'll take more time but it'll be quite the piece when done.