Monkey island is fun, though I feel the episodic delivery took away a lot of the charm previous games had. The story just feels disjointed.
Sam & Max, however, are a different plate. Story feels disjointed in the first two seasons (though that's kind of intended, you're not meant to have played the previous chapters to understand whichever you're playing), but season 3 took episodic gaming and made it simply awesome. The Sam & Max games are simply the best Telltale has put out.
Jurassic Park is considered to be crap by most people. I refrained from buying it after I read it was a quicktime clickfest, so can't speak for myself.