Same here. Safari is the speed king as far as I'm concerned. The only other browser that comes close is Opera.
Another Opera appreciator! We're slowly growing in number. Haha.
So, my "experiment" is done (the quotation marks are there on purpose). Some background: I have a 2.1 C2D MB with 4GB of RAM. I also want to suggest that the results here may not be unique to Safari nor am I out to make Safari look good or bad.
Results
I took memory usage info every hour for a seven hour period so there are eight readings in total (I counted the initial values). Here's what I found:
The drastic change from 2:10 to 3:10 was caused by running the SunSpider javascript benchmark. What's surprising is that Safari had to eat up close to 1.2GB just to make it through the benchmark (for some reason).
Next up, Flash video:
There seems to be a slight bump and then it seems to level off (perhaps it's worth noting that it was two 20 min. video and not one 40 min. video). Note the Flash version - I am using the 11 beta so I don't know how this would have affected the results compared to 10.3.
Take all of this with a grain of salt as this was very unscientific. I thought it might be interesting nonetheless.
Here is the spreadsheet with some more data regarding each measurement.