Generally, I do not pay full price for a game. Too often, a "AAA" title will drop down 20-30% a few months after release, so I just don't consider paying the premium to have it on day one. There are a few games out there that were certainly worth $60. I'm only adding in current-gen games.
I'm a sucker for Bethesda's games and Oblivion in particular. It hasn't aged well, and I always felt like Morrowind was a better game. However, Oblivion is still a wonderful title with a sweeping scale and lots to do. It tends to get a bit repetitive towards the end, but I loved getting lost in Cyrodiil and trying new spells and skills out throughout the game. By the end I had an unstoppable juggernaut who could blow through everything. I'd spent so much time building that powerhouse that it was completely satisfying to fuck up everything in my path.
According to GB's stats, I've played Rock Band 2 on 169 days. My sessions are usually at least an hour, meaning I've played between 169 to somewhere in the vicinity of 4000 hours. If that's not worth $60, I don't know what is. Hands-down I have played more RB2 than any other game in my entire life. It's interesting in a way, because I was completely disinterested in Rock Band when it first came out. However, after seeing RB around, I eventually realized how far superior that franchise is to Guitar Hero. That's not a knock against Activision; it's a congratulations to Harmonix for making such an amazing game. I didn't include RB1 on this list because I didn't pay full price for it.
After GTA V, I didn't expect to grab another sandbox game from Rockstar on launch day. While it was undoubtedly an amazing game, objectively, I just didn't care for it. But the intersection of seeing RDR in action and having nothing else to play at the time made me give it a shot. Boy, was it worth every penny. The single-player campaign was amazing, and I had great success working with other teams in the multi-player. There was a good balance of having enough story and general "fucking around" time that playing it was always a treat.
Fallout 3 has a good sense of humor and a great story. Also, I visit DC pretty frequently, so it's really cool to see it nuked to hell. I've gone through the game three times, plus picked up all of the DLC. I've spent over 300 hours playing Fallout 3. But the quantity of time alone does not make this worth $60. The sense of exploration, feeling of constant danger, and steady progress of your character's skills and equipment kept my motivation for playing quite high throughout the game. That they set one DLC pack in my hometown of Pittsburgh just makes it that much sweeter.
Like Yahtzee Crosshaw said, this package would be worth it for Portal alone (well, not really but pretty close). There is an awful lot of Source engine goodness in this box. Every game is well designed, fun to play, and repeatable. I'd already played Half-Life years ago, but it still packs the same punch.
I debated DQ-ing this game from this list because it was only $40 at launch. Truthfully, I would have paid $60 for it. At the time of its release, this was THE fighting game; everyone in the community played it. Unfortunately, a lot of the community left after MvC3 came out. I tried MvC3 but didn't like it, and while I liked MK9 I always had trouble playing it online. Neither game captures the same amount of fun and frustration as playing SSFIV online.
Obviously I like Rock Band, so of course I'd put RB3 on this list. Truthfully though, it wouldn't have made the cut if they had just added some new songs and touched up the UI again, like they did for RB2. The new goals system, addition of pro modes and harmonies, as well as the minor tweaks and updates made this game the penultimate fake band experience. I'm not sure where they could go from here, as they've added just about everything I wanted from this series since it first debuted.
