Firefox is great!. Here is the user.js that I maintain:

//Extentions Essential
// CuteMenus 2 - https://addons.mozilla.org/extensions/moreinfo.php?id=660
// SessionSaver - https://addons.mozilla.org/extensions/moreinfo.php?id=436
//                http://adblock.ethereal.net/alchemy.cgi/SessionSaver
//                http://forums.mozillazine.org/viewtopic.php?t=47184
// Greasemonkey - https://addons.mozilla.org/extensions/moreinfo.php?id=748
//                http://greasemonkey.mozdev.org/

//Extentions Good
// Flashblock - https://addons.mozilla.org/extensions/moreinfo.php?id=433
//              http://flashblock.mozdev.org/
// MozEX - https://addons.mozilla.org/extensions/moreinfo.php?id=40
//         https://nic-nac-project.de/~kaosmos/mozex107-en.html
//         http://mozex.mozdev.org/
// Mozilla Archive Format - https://addons.mozilla.org/extensions/moreinfo.php?id=212
//       http://maf.mozdev.org/
// Mouse Gestures - https://addons.mozilla.org/extensions/moreinfo.php?id=39
//                  http://optimoz.mozdev.org/gestures/installation.html

//GreaseMonkey Essential
//http://userscripts.org/scripts/show/741 http://jzig.com/accessify.user.js
//http://userscripts.org/scripts/show/972 http://www.lafferty.ca/software/greasemonkey/sourceplease.user.js
//http://neugierig.org/software/greasemonkey/unembed.user.js

//GreaseMonkey Good
//http://userscripts.org/scripts/show/688
//http://userscripts.org/scripts/show/955 http://www.holovaty.com/code/firefox/greasemonkey/google_suggest.user.js
//http://userscripts.org/scripts/show/1295 http://ftp.iasi.roedu.net/mirrors/mozdev.org/greasemonkey/linkify.user.js
//http://userscripts.org/scripts/show/713 http://gbsmith.freeshell.org/greasemonkey/upc_a_linkify.user.js

//http://www.stewarts.org.uk/stuff/IMDBAge.user.js

// Can be set from UI
user_pref("accessibility.typeaheadfind", true);
user_pref("browser.cache.disk.capacity", 262144);
user_pref("browser.download.defaultFolder", "/home/thomas/scratch");
user_pref("browser.download.dir", "/home/thomas/scratch");
user_pref("browser.download.folderList", 2);
user_pref("browser.download.manager.closeWhenDone", true);
user_pref("browser.download.manager.retention", 0);
user_pref("browser.enable_automatic_image_resizing", false);
user_pref("browser.history_expire_days", 31);
user_pref("browser.startup.homepage", "about:blank");
user_pref("browser.tabs.autoHide", false);
user_pref("browser.tabs.warnOnClose", false);
user_pref("dom.disable_window_flip", true);
user_pref("dom.disable_window_move_resize", true);
user_pref("dom.event.contextmenu.enabled", false);
user_pref("intl.accept_languages", "en-gb, en");
user_pref("intl.charsetmenu.browser.cache", "ISO-8859-1");
user_pref("network.cookie.cookieBehavior", 1);
user_pref("network.cookie.lifetimePolicy", 2);

// Handy quick change
user_pref("network.proxy.ftp", "wwwcache");
user_pref("network.proxy.ftp_port", 3128);
user_pref("network.proxy.gopher", "wwwcache");
user_pref("network.proxy.gopher_port", 3128);
user_pref("network.proxy.http", "wwwcache");
user_pref("network.proxy.http_port", 3128);
user_pref("network.proxy.share_proxy_settings", true);
user_pref("network.proxy.ssl", "wwwcache");
user_pref("network.proxy.ssl_port", 3128);
user_pref("network.proxy.no_proxies_on", "127.0.0.1, localhost");

//user_pref("network.proxy.type", 0);
user_pref("network.proxy.type", 1);

// Not set in UI
user_pref("keyword.enabled", false);
user_pref("browser.tabs.loadFolderAndReplace", false);
user_pref("browser.xul.error_pages.enabled", false); //needs showfailedurl
user_pref("network.http.max-connections", 128);
user_pref("network.http.pipelining", true);
user_pref("network.http.max-connections-per-server", 32);
user_pref("network.http.max-connections-per-proxy", 32);
user_pref("network.http.pipelining.firstrequest", true);
user_pref("network.http.pipelining.maxrequests", 8);
user_pref("network.http.max-persistent-connections-per-proxy", 32);
user_pref("network.http.max-persistent-connections-per-server", 32);
user_pref("network.http.proxy.pipelining", true);
user_pref("nglayout.initialpaint.delay", 0);
user_pref("capability.policy.default.Window.print", "noAccess");
user_pref("layout.frames.force_resizability", true);
user_pref("privacy.popups.showBrowserMessage", false);
user_pref("security.warn_entering_secure", false);
user_pref("security.warn_leaving_secure", false);
user_pref("security.warn_submit_insecure", false);
user_pref("browser.blink_allowed", false);
user_pref("browser.cache.memory.capacity", 32768);
user_pref("browser.cache.disk.parent_directory","/home/thomas/.mozillacache");
user_pref("browser.goBrowsing.enabled", false);
user_pref("browser.preferences.lastpanel", 0);
//user_pref("general.useragent.override","");
//user_pref("network.enableIDN", false);
//user_pref("general.useragent.override", "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.4) Gecko/20011128 Netscape6/6.2.1");
//user_pref("general.useragent.override", "Mozilla/4.0 (compatible; MSIE 6.0; Windows 98)");


// UI Control
user_pref("dom.disable_window_open_feature.close", true);
user_pref("dom.disable_window_open_feature.minimizable", true);
user_pref("dom.disable_window_open_feature.scrollbars", true);
user_pref("dom.disable_window_open_feature.status", true);
user_pref("dom.disable_window_open_feature.directories", true);
user_pref("dom.disable_window_open_feature.location", true);
user_pref("dom.disable_window_open_feature.menubar", true);
user_pref("dom.disable_window_open_feature.personalbar", true);
user_pref("dom.disable_window_open_feature.resizable", true);
user_pref("dom.disable_window_open_feature.titlebar", true);
user_pref("dom.disable_window_open_feature.toolbar", true);
user_pref("dom.disable_window_status_change", true);
user_pref("browser.block.target_new_window", true);
user_pref("security.warn_submit_insecure", false);

// Mozex Extention
//user_pref("mozex.command.mailer", "/usr/bin/kmail -s %s -c %c --body %b %a");
user_pref("mozex.command.source", "/usr/bin/gvim %t");
user_pref("mozex.command.textarea", "/usr/bin/gvim -f %t");

// Session Saver
user_pref("sessionsaver.settings.autoload", true);
user_pref("sessionsaver.settings.concatenate", false);
user_pref("sessionsaver.settings.dontwarn", " true");
user_pref("sessionsaver.settings.nofx", true);
user_pref("sessionsaver.settings.overwritetabs", true);
user_pref("sessionsaver.settings.overwritewindows", true);
user_pref("sessionsaver.settings.shutdown", true);
user_pref("sessionsaver.settings.shutdownsave", false);
user_pref("sessionsaver.settings.snapwindows", true);