Dropbox - Cloud storage
Box - Cloud storage
Boid - Twitter Client
Inka File Manager - File Manager
Disk Usage - Shows what your storage is split into?
Astrid RC - Tasks app http://blog.astrid.com/astrid-4-0-release-candidate/ (Not in market yet)
Gigbeat - Scans your music and notifies you of upcoming gigs
Google Offers - (Can't validate this as I live in the UK)
SyPressure - Let's you use your phone's baromter as a barometer!
Reddit News - A Reddit client
imo - an IM app, some use of holo, but also the occasional annoying iOS-esque element
EggDropp - Local classified ads
SoundHound - The lesser known cousin of Shazam
Android System Info - Pretty self explanatory
Remote Transmission - Remote for "Transmission" bittorrent client
StumbleUpon - Content discovery service - Holo themed, but with textured elements added, making it less cohesive.
Google Reader - Cloud based RSS reader
Crackle - Free film app
GroupMe - For group texting - Uses holo, but with some iOS style textured elements
HipMunk - Hotel and flight search
Pulse - News reader
Vevo - Music video app - Very poorly customised altered version of holo dark
Timetablr - For time tabling!
Online Radio - For playing online streams
Zinio - Magazine reader
Mentions - Track who's talking about your site
Bonfire - 37 signals campfire app - ?!
HoloNotes - Notepad
Shot Control - Camera
BeyondPod - Podcast manager/Player
Ultimate Stopwatch & Timer - Self explanatory
QuickPic - Photo gallery
Audio manager - Self explanatory
Maildroid - IMAP/POP3 Email client
PermissionAware - Highlights app permissions
MLB at Bat - Baseball apps - I'm only barely lettign this one through though!
OI File MAnager - File Manager
Nova Launcher - Home replacement
Robot Bird - Twitter Client