To make your browsing experience a pleasure and also benefit from a great development tool, Firefox is key. Here is my list of must-have extensions:

• DOM Inspector – inspect browser dom, really good for debugging DHTML
• FireBug – helps on any JavaScript error, much like IE Script Debugger
• TamperData – allows header information display and tampering
• WebDeveloper – a great one for web development
• Mouse Gestures – this one will make you dependent
• Sage – RSS feed reader
• FlashGot – integrates with various download managers
• Dictionary tooltip – see word meanings in various languages
• Google Notebook – take your notes with you wherever you go.