Imagine you could tell you game master what kind of game you wanted to play. Not just what rule set but specifically what parts of the RPG session make you think to yourself "now this is fun!" You have not thought about it? Well, think about it now. Think about what items in a session keep you coming back. Below I've detailed a few for consideration.
Combat: Do you feel a jolt of energy when the GM says "roll for initiative!"? Are you into the tactical situations that occur within the group? Can someone lay down suppression fire? Can you flank the enemy? Will the rogue stay out of trouble?
Maybe you view combat more as an individual achievement. Your character going toe to toe with the ogre barbarian while the rest of the party deals with the goblins. Your mage's perfect use of the Rock to Mud spell to stop the charging behir. The rogue's perfectly timed back stab that spoils the evil sorcerer's spell. Just to name a few.
Puzzles: Maybe you like it better when the GM gives you something to figure out. A treasure map missing some details. There could be a series of statues that need to be moved in some sequence. Perhaps a magical fountain that only works when a special cup is used and there is a table full of cups next to it. It could be something as simple as a murder mystery.
This is one of the more difficult things to add to a game. You can make the puzzle too hard for your players to figure out and end up rolling a skill check for the character to figure it out. The puzzle can also be too easy and the discussion and teamwork you imagined for the party never materializes.
to be continued....