I like Canon's too. Canon G2/G3 is probably a good choice if going with Canon. Check out
http://www.dpreview.com to see which cameras are popular and to see their reviews. Unless you want to carry it around with you everywhere you go, go with the full size cameras with the bigger lenses instead of a compact. You'll get better Macro shots if that's what you need. Get an ultracompact only if keeping it in your shirt pocket is more important.
Personally, I got the Canon Powershot S40 which has the same features as the G2 but in a compact form. However, it is not tiny and still isn't all that comfortable in a pocket. If I were to do it over again, I would get 2 cameras: Canon G2 for taking great quality pictures of my tanks and for going on vacations, and a tiny lower resolution camera like one of the Canon Elf series and keep it in my pocket for the ability to take pictures at any time while on the road.