I’m not sure supplements are ever fun … but they can help with getting enough protein if you’re lifting or an additional energy boost via creatine … protein powder can taste nice but you need to watch out for macros if it’s too delicious, I’ve never had a nice creatine.

Or by fun do you mean preworkouts? I think there’s limits to preworkout value when what you really need for workout energy are easily digestible carbs over caffine or other cruft.