My boss at work just returned from a vacation with his family. They flew to Florida, spent several days at the Disney parks, then went on a five-night cruise around the Carribean. He described to me how buying twelve-month passes to the parks saved his family money, since the cost for a family of four to go to Disney is something like $354 per day (tickets and parking -- not counting food, lodging, or souvenirs). This is a typical vacation for them -- one they've taken once or twice per year going back almost a decade now.
I have another friend at work who likes to spend time with his (adult) son working on and then driving/piloting various motorized conveyances -- motorcycles, ATVs, snowmobiles, Jet Skis, etc. He's always saving up to buy a new engine or some other upgrade for one of the machines.
I have a few other work friends who own "ski cabins" up in the mountains that they use as a base of operations for their frequent ski trips. I have yet another acquaintance at work who is a serious computer gamer -- always telling me about the latest game or equipment he's bought and is spending time on.
The reason I mention all of this is not to commend or criticize any of these behaviors. I am definitely an advocate for taking time to enjoy life -- "working to live" rather than the other way around. The reason I mentioned these folks is because it occurs to me that the sorts of things I am naturally drawn to, and which I try to partake in whenever I have an opportunity for some recreation time, are things which don't cost nearly as much as any of the things that a lot of the people I work with do. The activities I enjoy usually require a bit of upfront cost, but very little in they way of ongoing/maintenance costs. For example:
Hiking and Backpacking. I love getting outside and seeing the scenery. Hiking up to a high point in the mountains in this part of the country is a rewarding experience. My wife and I have spent many a day together on the trails, either for short day trips or for longer overnight/backpacking hikes. But hiking costs very little. All you really need is a good pair of boots or trail shoes and a backpack. Nothing has to be fancy. Most of the trails around here are free or have very nominal parking fees, which can be alleviated through the purchase of a yearly pass for around $25 (just over $2 per month). For the winter months, a good pair of snowshoes comes in handy.
Ultimate (frisbee). What a great game. I discovered it in college and have been playing informal/pickup games ever since. It's often possible to find space to play on a free field in a park. Discs cost around $10 each. Cleats are the only special equipment that I use, and not everyone uses them (some even play barefoot).
Board games. Countless hours of fun can be had for a very small up-front cost. This offers an excuse to get together and socialize with others on a regular basis -- we've been playing with our group about once a week. If everyone brings their own food and beverages, game nights can be a very inexpensive way to have fun. My personal favorite these days is Settlers of Catan (of course including the Seafarers and Cities and Knights expansions).
Other favorite pastimes include reading (usually library books or free eBooks from sites like Project Gutenberg), blog writing and reading, and bicycling (primarily a commuting exercise for me).
I guess I should consider myself lucky that I'm naturally satisfied by experiences that don't come at a high price. I prefer using my muscles over using motors or engines. I'm not drawn to activities that require a lot of high-priced equipment or regular usage fees (like hockey or golf or skiing). I also hit the jackpot when I found a woman who appreciates the same sort of low-cost entertainment as I do. We've had some great vacations backpacking in some of the national parks for very little cost -- transportation to the parks being the main expense.
For this reason, I expect that once we are able to break away from our full-time jobs and have more hours to fill with recreation, we won't have any trouble filling our days with fun and enjoyment without significantly increasing our expenses.