How to play avi, flv, dat files in Apple Mac book?

Quicktime player requires paid upgrade for playing most codec. You don't need that. You can have same functionality and even better codec support free of cost. You may want to use the players that have the codec support mentioned in your requirement. Here are some of the following players that may work with your Macbook.

1. VLC for Mac. This adds most of the popular codec on the web. And you can easily play almost all popular files from the internet, both audio and video files.

2. Winamp. It does work on Mac OS too. You can play the above audo and media formats on the Mac OS with that.

3. GOM Player. Another player similar to VLC. Here you can see that the player does work out for the playing of most of the audio and video format.

You may want to try VLC as that should be more than enough for your codec and media playing experience. If it does not play some codecs then try out other players. But for Mac most of the formats are played by VLC. So it should be more than enough.

You can play avi,flv,or dat file on your Apple Mac book by using the applications listed below. You will have to buy this app from the Mac App store with your Apple ID. I will recommend you to go for VLC media player as this player support maximum of the files from internet.

1. VLC Player
2. Elmedia

I don't think VLC player is available in the App Store. They have removed VLC player from the store. As of now the best player available is Elmedia Player. The second choice you can go for is Supreme Player.

1) Elmedia Player
It can Play any file type, be it AVI, MP4, LV, WMV, MKV, MP3, M4V etc.. it is an all in one solution, that does not need any additional plugins or codecs

2) Supreme Player Lite
The supported formats include MPG, MPEG, MPEG 2, VOB, DAT, MP4, M4V, TS, RM, RMVB, WMV, ASF, AVI, MKV, 3GP, FLV, MOV, H264/X264 1080p/720p HD video and all audio formats

As far as I have experienced, VLC Media Player is the best videos player to play any of the video files with ease on your Mac. It supports almost all codecs as one of the responses above has clearly indicated. But, however, if you cannot find VLC media player in your app store for any reason, you can visit the official link of VLC at VideoLAN.org/VLC and download the Mac version for your device. Open the DMG file and drag VLC icon onto your Applications folder. You can then drag the VLC icon from the Applications folder to your dock. You may need to confirm and trust the app.

For viewing the DAT files - if it is not able to open through VLC, you can use a software to convert the DAT file into an MPEG format. You may use the tools like DAT converter for the purpose. Once converted, you can play them in VLC.