For a long time now I have used Firefox, since 1.0 days. It's also always been a RAM hog for me, yes I am one of those people. It's also, at least for awhile been having freeze/skipping issues, where everything from clicking a button, scrolling, to videos would freeze, then go, then freeze. Now I figured I have to live with this because I have Enabled Extensions:  - Adblock Plus 1.1.3 - Better GCal 0.3 - Better Gmail 2 0.9.8.1 - Better GReader 0.8.3 - Better YouTube 0.4.3 - BetterPrivacy 1.47 - BookmarkMenuHider 0.1.0 - Boost for Facebook 9.9.2 - CheckPlaces 2.1.0 - CLEO 4.3 - ColorfulTabs 4.3 - Combine Buttons 0.4.8 - Compact Menu 2 3.1.1 - Coral IE Tab 1.80.20100224 - CustomizeGoogle 0.76 - CyberSearch 2.0.4 - Download Statusbar 0.9.6.7 - Exch 1.4.5 - Extended Statusbar 1.5.4 - Fasterfox Lite 3.8.2Lite - Favicon Picker 3 0.5 - FEBE 6.3.2 - Fission 1.0.9 - Forecastfox 0.9.10.2 - Free Realms Installer 188.8.131.52 - Gmail Manager 0.6 - gReactions 0.1e - ImageHost Grabber 1.6.3 - Integrated Gmail 2.6.0b2 - Java Console 6.0.18 - LastPass 1.66.0 - Linkification 1.3.8 - Locationbar² 1.0.5 - Memory Fox 1.4.4 - Menu Editor 1.2.6 - Menu Icons Plus 1.8 - MR Tech Toolkit 6.0.4 - NoScript 184.108.40.206 - Omnibar 0.6.8.20100227 - Organize Status Bar 0.6.4 - Personas 1.5.1 - Perspectives 3.0.3 - RAMBack 1.0 - Save File to 2.0 - Screengrab 0.96.2 - SearchPreview 4.1 - Shareaholic 1.9.6 - SkipScreen 0.3.20091214_AMO - Smart Bookmarks Bar 1.4.3 - SmoothWheel (AMO) 0.45.6.20100202.1 - Speed Dial 0.9.5 - StumbleUpon 3.63 - Stylish 1.0.8 - Stylish-Custom 0.7.2 - Tab History 1.0.6 - Tab Mix Plus 0.3.8.2 - Toolbar Buttons 0.6.0.8 - Update Notifier 0.1.5.5 - URL Fixer 1.6 - visualizeus 0.5.3 - Web Developer 1.1.8 - Xmarks 3.5.7 Installed Themes:  - Default And I also have 42 Stylish Scripts installed as well (even though I believe those don't take as much). And I also have 8 to 15 tabs open at any giving time, and my Firefox only restarts if I install something new. So I came to expect my Firefox to run between 300MB to 1GB at any giving time. The last week I have been fine tuning the scripts, replacing bulky addons with better ones if possible, making sure I have the least amount of them as well. I also found an amazing addon called Memory Fox which I think did most of the work. Don't know what it does. But with that addon and everything else I have fiddled with, I am running between 5MB to 150MB at any giving time now. It's been running nice and smooth like a charm the past 3 days now, I don't know if it will always last, but its awesome.