I personally use the following addons for more than 2 years now, therefore I can recommend them.

• Advanced Trade Skill Window (ATSW)
• Atlas
• Atlasloot Enhanced
• Auctioneer
• Deadly Boss Mods
• Decursive
• Gatherer
• QuestHelper
• Recount
• Titan Panel
• Wow Instant Messenger (WIM)
• X-Perl Unit Frames