If you are new to Mac OS X, here are a few applications I recommend you use that can make your experience with your Mac a whole lot better.
Cyberduck
Cyberduck is an open source FTP and SFTP client. It is fast and powerful with an easy-to-use interface. This graphical application offers support for multiple connections, bookmarks, resumable download and much more. Cyberduck also supports Mac OS X Keychain and Bonjour networking. In addition, this application is also able to open some files in external editors like TextWrangler, BBEdit, etc. No matter which language you understand, Cyberduck supports multiple languages including English, Dutch, Korean, Spanish, Turkish and many more.
iBackup
Everyone faces drive failures, accidental deletions, etc and all such mishaps can be remedied if you had backed up your data. To backup your stuff, there are many available tools but for Mac OS X, and iBackup is great. iBackup is a reliable, user-friendly and secure application that lets you backup and restore your system and application preferences with easy. iBackup also provides you with the option of a selective backup or sync that only backs up the modified files. Further, iBackup also uses plug-ins that let you backup your settings like time, desktop picture, firewall, Bluetooth and more.
StuffIt Expander
Expander is great decompression software that has an ability of decompressing virtually everything that you throw at it. Mac OS X too can decompress files and folders but Expander also allows depression of many file formats that Mac can not handle, like .sitx, .tar, .sitx, tgz and many more.
VLC
You might encounter an online video or audio file that your current media player cannot recognize. You probably use QuickTime or Windows Media Player for Mac but these sometimes lack a codec required to play various media files. Check out VLC player, which offers high compatibility when playing different file types. It is capable of playing virtually every audio and video file without compromising quality of playback.
Adium
Adium is an open source instant messaging client with a sleek interface. It supports many instant messaging protocols like AIM, ICQ, MSN, Google Talk, Yahoo and more. Adium has a tabbed messaging feature that allows the combination of multi chats into any combination of windows. A single window might contain five different tabs and the other might hold 10 and so on. This tabbed messaging feature let you chat with fun while providing maximum efficiency