by Adam Pash at http://lifehacker.com/software/ubuntu/hack-attack-top-10-ubuntu-apps-and-tweaks-195437.php
Taking a page from Mark Pilgrim's essential software list, I've included the necessary command line code to install most of the applications below; if you don't like Terminal, you can use Ubuntu's very friendly Add/Remove software application interface (Applications -> Add/Remove...). Where I haven't included the apt-get line, follow the instructions in the link.
As I said last week, Automatix will get your system ready to play nice with proprietary codecs and the like, but it can also install a lot of really useful apps, from Picasa and Google Earth to several of the apps on this list. Automatix is a great way to get a lot of applications installed in a hurry.
Beagle is the Spotlight/Google Desktop search app for Linux. However, think more Spotlight than Google Desktop (which is a good thing, because Google Desktop can suck at times). Beagle indexes your files and lets you construct quick, powerful file searches.
apt-get install beagle
3. Gnome Deskbar Applet
The Gnome Deskbar Applet is sort of a cross between Spotlight and Quicksilver. Basically it's a great app launcher and then some, with plugins designed to integrate more search options than you can shake a stick at, from live Google searches to integration with Beagle.
To use the Deskbar Applet, right-click the top panel and select Add to Panel... and find Deskbar Applet (incidentally, there are a lot of other great tools in the Add to Panel... dialog worth checking out). It's no Quicksilver, but it's better than any app launcher/search tool available on Windows.
apt-get install deskbar-applet
It's no secret that we love us some VLC, so there's no reason not to keep loving it on your new Linux distribution. VLC can play virtually any file format you throw at it.
apt-get install vlc
As a bonus, you can also setup VLC as a plug-in for Firefox.
It should go without saying at this point, but no operating system would be complete without Firefox. Ubuntu ships with Firefox out of the box, but it never hurts to emphasize something you love so much. Of course, you will want to add any number of Firefox extensions.
apt-get install firefox
I didn't know that love between a man and a music player was possible, but amaroK's seamless integration with Wikipedia, lyrics and album cover look-ups, and MusicBrainz have me questioning the laws of nature and propriety. Oh, and don't worry - it'll sync to your iPod with its eyes closed.
apt-get install amarok
Even though Google doesn't, for some strange reason, provide a version of the Gmail Notifier for Linux, that doesn't mean you're out of luck - the resourcefulness of the open source community comes to the rescue!
apt-get install checkgmail
8. Add NTFS Read/Write support
If you're switching from Windows, chances are you've got lots of data stored on an NTFS (New Technology File System) formatted drive that you're not ready to get rid of. This used to be a major problem, since Linux isn't able to write files to NTFS drives. Or at least that used to be the case. Luckily the Linux-NTFS project has built a driver to overcome those limitations.
9. Turn off the system beep
You know that annoying, shrill beep that comes not from your speakers, but rather inside the depths of your computer called a system beep? I hate it, but Ubuntu likes to use it when, for example, I'm searching for text in Firefox and I get to the point where the text doesn't match anything. In Windows, this invokes a fairly annoying noise. In Ubuntu, it's the system beep, which is even worse. Here's how to disable it:
If you decide you miss it, this will re-load it:
10. XGL/Compiz = Purdiest graphics you've seen in a while
The XGL/Compiz one-two punch offers an incredible window management environment for your Ubuntu installation. My video card isn't quite up to snuff for handling these kind of accelerated graphics (it's really kind of a weenie), and the architecture hasn't got all the kinks worked out, but this is definitely the most exciting GUI I've seen in a while.
Your mileage may vary with XGL/Compiz, but here are the instructions that worked for me (note: over-the-top thrash metal not included):
UPDATE: Jason from Tectonic says that this article on using Compix/XGL on Ubuntu is the new and improved version of the article linked below, so you might want to check it out instead.
All right, I'll admit - Frozen Bubble isn't the most important app on the list, but I love this game, which is why it gets the coveted number 11 slot. Play it.
apt-get install frozen-bubble
Missing must-have applications?
While this list is a collection of my favorite programs and tweaks for Ubuntu, it is by no means a comprehensive list of the Linux programs that can give you your Windows fix. If you're considering making the switch to Ubuntu but you are worried you won't be able to find a program to satisfy your needs, let us know about it in the comments or at tips at lifehacker. Also, if you're a Linux user with your own favorites, I'd love to hear them.
As for me: While I am really happy with all of the programs I've found for Linux that replace their Windows counterparts (switching to Linux has never been easier), I have to admit that I'm in desperate need of a text replacement tool along the lines of AutoHotkey or Textpander. I would kill for some quick text replacement right about now.