Everyone is different; what motivates one person may demotivate another. It's hard for us to know what your motivators are.
Since you have five bikes, I'd suggest riding each of those five bikes and see what you enjoy. But even that suggestion is influenced by my motivation for enjoyment; other people are motivated by competitive drives, desire to be physically fit, etc.
Nonetheless, if your bikes are of different genres, like road, mtb, hybrid, then I suggest riding each of those bikes in the manner they were designed to be ridden. Kit up and do a road ride on the road bike. Put on some baggies and ride the MTB offroad, jeans and a tee and cruise some paths on the hybrid. After all that, see what sticks - what did you like? Do more of that.