As others have said, less stress on your body and better endurance as you lose weight. Your legs will be better able to do their job as your shock absorbers if they're handling less weight with the same amount of muscle strength. Additionally, your range of motion improves.
I've always struggled with my weight, I know where you're coming from. With 2 kids under the age of 5, and both my wife and I working full time, including some nights and weekends, it's hard to find time for yourself, and easy to make unhealthy food decisions for the sake of convenience. I'm still working to recover from the last few years. I've lost 27lbs since last February and still have another 16 to go to reach my target. I made some lifestyle changes that I felt would be easier to maintain. Mainly, eating more fresh foods, cutting out a lot of the unhealthy snacking I was doing, drinking more seltzer (because it's more appealing than water to me), and less beer and couch time. I didn't undertake any rigorous exercise routine, but instead made choices like keeping up on my yard work more, playing outside with the kids more, or going out to the garage and doing my woodworking for an hour or so at night before I sat down in front of the TV.
One of the motivators I used was setting a goal to go from a 2X ski shell to an XL, and I'll be ordering my new shell in the next few days. You can find a shirt or two in your closet that you really like, but aren't comfortable with how it fits. Make that a milestone. Or, make your goal to go down a notch in your belt. It's more fun to pick milestones that you can realize on the way, than focusing on the final number. I've found, so far, that setting a goal at an achievable 5lb loss at a time keeps me more motivated than a goal that is 15 or 20 pounds away. I haven't set a timeline, I feel like if I did, I would either work at an unmaintainable pace and gain it back, or would not meet the deadline and feel bad about it. If you know you're a few pounds away from that goal, that seems to have been enough motivation to get there.