Honestly, I have been playing Runescape for over 7 years. That's probably more years than most people who have played. I've been playing it since nearly the beginning. On that note, I've loved the time I spent into playing the game.
It's not technically the game per say, but the people that I've met through it. Sure Runescape has in a way made my social skills a little better, although I still consider myself a loner. I've also managed to handle money better and I have been able to save money instead of spend it in real life. But the real reason why I value my time spent on this game is because of the people I've met.
In Classic, I was around 10 years old when I started. I was immature and ignorant and I was pretty innocent towards things. The community of the old Runescape taught me a lot of things. People showed me generosity, sincerity, and much more which I reflected later on because of what they taught me. I became a well rounded individual after a few years and I was nice and generous to everyone.
Now that I think about all the years spent of playing, I really appreciate all the friends I've made. I remember meeting Nocred and Murloc, both from Canada and we three clicked pretty fast. I considered them good friends. I also met The Llama and us four hung out from time to time. These guys were my closest friends that I've had. I talked to them until they quit and I've never seen them again. I still value the time we spent together and made me appreciate people from other countries.
I also met Brian and Hunter through the game and they reminded me of Nocred and Murloc. So when I talked to them for the first time, I felt like we really clicked as well. Even though we just talked and did things together in game, I honestly believe we three had a good bond together.
I also remember meeting Chubidubero, aka Wind God. He has this personality which I can't really describe but it's so welcoming and sincere that really drew me to him. He's a really good friend and I'm glad I met him just like the others. I still talk to him from time to time on MSN when I get on and he's the only person I've kept up with from Runescape who has quit.
I also met Chris and Remon on Runescape who I really like. They probably live the furthest away from anyone else that I know. They are always enjoyable to talk to in game and are fun to hang out with. I also started to talk to them on Live, which was awkward at first for some reason, but now I like it.

I know there are plenty of people I could keep talking about, but these are just a few of examples.
Long story short, I'll always be happy about the time I spent playing Runescape purely because of the people I've met. I don't think I'll ever be angry at "all the time I've wasted" on playing this game. I've grown up a lot since I started and I can proudly say, I cherished every moment of it.