I would say the best too is Camtasia Studio which has more features than you may think you need but it really is worthwhile if you want to do a lot of Screen Captures to produce online training programmes. I have created in the past online training in company specific software and processes.
Since becoming a teacher I have devised many opportunities for using pre recorded tutorials that the students can return to when they are ready to listen (usually when they realise that they need to learn it to do the assignment)
You can download the free 30 day trial first to try it out before buying.
The following list of free alternatives are OK if you cant foot the bill for Camtasia.
Camstudio – With Camstudio you can record all screen and audio activity on your computer and create industry-standard AVI video files and using its built-in SWF Producer can turn those AVIs into lean, mean, bandwidth-friendly Streaming Flash videos (SWFs).
Jing – With Jing you can Snap a picture of your screen. Record video of onscreen action. Share instantly over the web, IM, email.
Windows Media Encoder – Windows Media Encoder is a powerful tool for content producers who want to capture audio and video content using the many innovations in Windows Media, including high-quality multichannel sound, high-definition video quality, and support for mixed-mode voice and music content.
Virtualdub – VirtualDub is a video capture/processing utility for 32-bit Windows platforms (95/98/ME/NT4/2000/XP), licensed under the GNU General Public License (GPL). It lacks the editing power of a general-purpose editor such as Adobe Premiere, but is streamlined for fast linear operations over video. It has batch-processing capabilities for processing large numbers of files and can be extended with third-party video filters. VirtualDub is mainly geared toward processing AVI files, although it can read (not write) MPEG-1 and also handle sets of BMP images.
Wink – Wink is a Tutorial and Presentation creation software, primarily aimed at creating tutorials on how to use software (like a tutor for MS-Word/Excel etc). Using Wink you can capture screenshots, add explanations boxes, buttons, titles etc and generate a highly effective tutorial for your users.
XVidCap – XVidCap is a small tool to capture things going on on an X-Windows display to either individual frames or an MPEG video. On Windows machines there are commercial tools like Lotus ScreenCam or Camtasia which do a very good job esp. for the purpose I was needing such a tool for: Software documentation, esp. installation procedures and such
FFMPEG – FFmpeg is free software and is licensed under the LGPL or GPL depending on your choice of configuration options. If you use FFmpeg or its constituent libraries, you must adhere to the terms of the license in question. If you do not, we will track down your project and list it in our Hall of Shame. To see how easy it is to comply, take a look at our license and legal considerations page.
Screen Toatser – No download. Compatible with Windows, Mac OS X, Linux. Capture videos of onscreen action in one click. Record screencasts, tutorials, demos, training, lectures and more. Share and stream videos online in Flash. Embed them on blogs and webpages or send them by email.
TipCam – Free screencast recorder for Windows. Record your screen and voice in a flash video (FLV format) and share it instantly at uTIPu.com
HyperCam – HyperCam captures the action from your Windows screen and saves it to AVI (Audio-Video Interleaved) movie file. Sound from your system microphone is also recorded.