My must have apps on Legend:

1) Voice to text (I use low res sense style)
2) Nexus One Gallery (3D gallery - way way better than stock and smooth too)
3) Voice Search (damn cool)

the first three is not included on stock legend

4) Gesture search (google's own app, very very useful for quick searching for stuff on your phone)
5) Lookout mobile security (antivirus)
6) Astro (file manager)
7) Handcent SMS (allow for more customization for messages and nice popup for quick reply)
8) FxCamera (Nice camera effect)
9) Juicedefender (extend battery life)
10) K9 Mail (better email app)
11) Ringdroid (make your own ringtones from mp3 files that you have)
12) The star online (malaysian news)
13) Barcode scanner (useful when you browsing apps online and want to scan QR code)
14) AppMonster (I use this to keep track of my apps)
15) Movie Finder (OMG so useful for moviebuff)
16) Tajm (nice looking literal clock)
17) Battstatt (nice looking literal battery status)
16) Widgetlocker (lets you customize the lock screen - even put widgets!)
17) Laucherpro (tired of HTC sense UI? use this and frankly this look way cooler and faster - cant use HTC widget with this though)
18) Beautifulwidget (Skinning clocks anyone?)
19) SwitchPro (Very very nice looking power management widget)
20) PureMessenger (superb widget that can combine all messages, email, facebook, twitter - skinable too)
21) Purecalendar (nice widget that integrate with astrid and other calendars)
22) Launch-X pro (nice apps shortcut widget)
23) Astrid (all my to do task using this)