For me, the most fun I've ever really had with aviation has involved ownership of a really cheap and simple aeroplane (in my case usually a microlight, but LAA aeroplanes can offer the same benefits).
You can buy a nice single seater for £1500+ in the microlight category or 2-seater for £3k+, and run it for around £30/hr all in with care and effort. The rewards - being able to fly 6 hours in the day for the price of an hour with an instructor in a Cessna, no longer having any requirement to be back at any time, learning to really understand that aeroplane as you are the only person to fly and maintain it, for me have always been massive.
Going up to the £15-£20k bracket,there are far more options, but the basic points are the same.
And of-course, if you've already bought it and maintain it, what reason is there not to fly it at probably £15/hr in fuel? So your flying, recency, and enjoyment levels will all go up massively.
This is not to dispute any of the other options suggested - but if it's really about enjoying flying being integral to your life this does it for me.
G