Firefox is generally a great browser, specially with the right set of extensions, but some of the UI simplifications can be a real PITA for advanced users. Misbehavior can usually be corrected by some obscure variable (often with even obscurer possibles values) in the configuration, the “only”; problem is finding it, here are the tweaks I usually do to new installations. (They can be applied most easily by opening the about:config url.
Of course there are no good values for everyone, otherwise Firefox would be using them.
(This one is a real nag in Firefox 3 if you have some LAN services using SSL!)
browser.xul.error_pages.expert_bad_cert = true
Enables inline accept button in the error page
browser.ssl_override_behavior = 2
Pre-fetch the certificate (two-click acceptance instead of four).
browser.enable_automatic_image_resizing = false
I use this mainly because it keeps the browsing area always with the same size.
browser.tabs.autoHide = false
Specially useful when dealing often with photos. Applies embedded color profiles to images if they contain one.
gfx.color_management.enabled = true
Source: Jeffrey Friedl's blog
I'll update this page whenever I find some other obscure option :)
Last edit: June 19th 2009