Safari is missing some features by default. Glims adds most of them in and the Safari Omnibar addon is also nice to have. Extension support and availability on Safari seems to be a bit lacking.
I don't know what you're complaining about font rendering. It is much better than on Firefox (though the difference is less obvious in FF4+) and is exactly the same as on Chrome.
I'm a web developer and use Safari, Chrome and Firefox. Firefox has slightly better development tools (Firebug) but is heavier, Chrome is really fast and Safari is most native to OSX. For the average user any of these will do just fine, it comes down to personal preferences. All render websites as expected, if your favorite website doesn't work right, blame its developers for writing HTML/CSS that is non-standard or poorly formed.
To me many of the issues others have posted in this thread stem from something else being wrong on their systems. I haven't run into any significant problems on the afore-mentioned browsers on my 2009 MBP (10.6, now Lion), my work Mac Pro (running 10.5 no less) and Hackintosh system (10.6, now Lion).
