I am just curious but why not go with mactheripper or handbrake rather than simply or liquid?
Why? What is better about them?
Mac the Ripper and Handbrake are used for ripping disks. SimplyBurns and LiquidCD are for burning disk images. They're not comparable because they do completely different things.
The best way to figure out which is best for you is to try them. They have similar feature sets and it pretty much comes down to personal preference. Another one worth looking at is Burn which, although having a very simple UI, can do transcoding of video to DVD and VCD for simple projects.
The thing is I don't have too much time to test out each one. Could anyone say what are the pros and cons of the dofferent burning programs?
As I already said, they're all disc burning programs with pretty much identical feature sets. One is as good as another. There's really nothing anyone can tell you that is not skewed by their own personal preference for the UI layout. For example, I could tell you that SimplyBurns has the best UI and LiquidCD sucks, but no doubt somebody else thinks differently.
When it comes down to it, they're close enough that it really doesn't matter. You'd be better off just downloading them and using one for the next disk you need to burn, and the other for the next disk after that. That way you don't take up additional time (it's a 2 minute download) and you've seen both. It's taken me longer to write this reply than it did to download and install LiquidCD (seriously, I just did it).
If you're just looking for personal recommendation, I use SimplyBurns at the moment.