The YucA is on Android? what?
My picks for stuff I do on my Nexus S:
Rom: Varies, currently CM9
Kernel: Varies, currently Trinity
Messaging: Gtalk, Kik
Email: Enhanced Email, Touchdown
Browser: Mini Dolphin
Widgets: Beautiful Widgets, Switchpro
Misc: SetCPU, AdFree, Alphascope, Barcode Scanner, BLN Control, Chrome to Phone, ConnectBot, Terminal Emulator, Cpu Spy, Docs to Go, DSPManager, Fast Burst camera, Quick Pic, Hulu+, Netflix, Newegg, Amazon, Paypal, Pandora, Plume, Rom Manager, Root Explorer, SeekDroid, SoundHound, SpeedTest, Sugarsync, Steam, SwiftkeyX, Tapatalk, Tiny Call Confirm, Titanium Backup, Voodoo Sound, Wifi File Explorer
And the typical Google Apps stuff...