you´re comparing three completely different things here and without knowing your taste it is really hard to give a recommendation. I am a clubber at heart and cocoon is easily my favourite night so my personal choice is very easy.
cocoon --> techno night for music lovers. the most diverse crowd of all of the techno parties on the island. great vibe - but I will admit it is not a night where the VIP normally gets packed.
lío - dinner show. very good food, great shows, but it comes with its price. I went once for the full experience but I wouldn´t pay it again - simply because to my personal discretion, a good dinner with a show doesn´t have such a high monetary value. but I understand everyone is different there and especially on holiday, people love to have an unique experience and things like lío and heart are exactly that. I´ve seen you seem to be coming to the island this month so if you haven´t got a booking yet for lío, chances are very small you´ll get a table. it is notoriously fully booked.
pacha - depending on your music taste this could be your middle ground between the two above. club night, big VIP area which on most of the nights is very busy too (there are exceptions). and there you could even combine it by having dinner at pacha restaurant first and then head into the club (either with or without VIP table)
happy to help, but without knowing preferences it´s rather tricky.