It's not completely fair to single any one browser out for memory usage these days. The trend is to move toward isolating each tab so they don't crash each other as easily, and that inevitably leads to increased memory usage. All browsers are going to be doing this if their developers have any idea what they're doing, and that definitely includes firefox and chrome.
Memory leaking is less excusable of course, and unfortunately chrome (firefox too, last time I used it) has plenty of that to go around. Right now it's hoarding 4 gigs of ram on my desktop machine. Now to be fair, about 800 megs of that is taken up by flash and we all know better than to be surprised there, but the majority of that memory usage is just plain old unintended, buggy behavior on behalf of the browser itself. If I were to restart chromium right now I'm sure the memory usage would be no more than a few hundred megs total once the tabs all loaded back up. That's just pathetic. I know this because I do have to restart it every few weeks due to its instability, and it never reclaims more than a few hundred megs whether I have 53 open tabs or 253 tabs.