I know most people don't use Macs, but if you are considering one and want to capture stuff, there are some things that you want to take into consideration:
1. Not all capture devices that work on Windows will be compatible with Mac OS X. This is because Mac OS X doesn't have a built in functionality for watching TV and stuff. If you want to record anything on the Mac, you need to have a compatible device. Here are the known and incomplete list of devices that will work on the Mac.
- Happauge 1445 HD-PVR
- Eye TV Hybrid/HD/250 Plus (comes with EyeTV Software)
- PCTV HD Pro Stick (801e)
Aside from the EyeTV HD and Happauge HD PVR, you are stuck with standard definition. If you decide to record in SD, obtain an S-Video adaptor for your game console so that the video looks clearer. Otherwise, you will have a lot of artifacts and other issues with the video quality.
A full list can be obtained at the
Elgato Website.
2. You need to have a copy of EyeTV installed. EyeTV Lite won't work since you won't be able to export the video and edit it in a video editor. As previously mentioned, this program is only compatible with the devices above.
3. For some older capture cards, it will have stuff in MPEG-2 format, which you can't edit. This can be solved in two ways. In EyeTV, go to Window > EyeTV Programs for the list of recordings.

Then right click the video you want to export and choose export. If your capture card doesn't export the full quality video in MPEG4, select Quicktime Movie and then the Options button and then settings.

If you have the option to use Apple Prores 422, use that. Otherwise, use Photo - JPEG and set it to best quality. For sound, use the highest bitrate for AAC possible. Then press OK and then save.
Alternative:If you have an MPEG-2 file, you can still convert it to a usable format providing if you have the MPEG-2 Quicktime component installed. Get a program called MPEG Streamclip and open your mpg file in it. Then go to file > Export to Quicktime. From there, you can choose the codec and fix the aspect ratio (854x480). Also, be sure to check the "Deinterlace Video" option before making the movie. You can also do this after exporting the video from EyeTV to fix the aspect ratio.

4. Have a video editing software ready to edit the recording. Since all new Macs come with iMovie, this isn't much of a problem. However, if you want to use a different editor, Adobe Premiere Pro and Final Cut Pro X are acceptable choices.
Another Consideration: Recording QualityEyeTV can record in different resolutions, but keeping it at the default settings can result in poor quality recordings. To fix that go to Eye TV Preferences > Devices. Then, set the recording quality of your device to "Best" or "High." The Encoding box will be different depending on what device you use.
Fixing Aspect RatioIf you have your PS3 set to use 16:9 and using standard definition cables, you might notice that the Aspect ratio might be wrong. To fix that, go to Preferences > Display and select the Stretch option. After that, it should display correctly.