Ok, let me start.
The most of all I like the mentalism tricks which would need any props or items to perform. Sort of impromptu. Therefore the majority of them are mind reading tricks since they are considerably easy to perform yet they tend to be extremely impressive to the spectator and/or audience.
Then I also like mentalism card tricks, since all you need is a deck of card, which I normally carry in my bag or pocket.
Recently I was selecting the best and easiest mind reading card tricks and here is my personal top3:http://www.learnmentalismtricks.com/3-mentalism-tricks-revealed/
Especially I like the last one since it doesn't need your presence and you can perform it over the phone. It just explodes spectator's mind normally:)
Everything you see is illusion.