Mass Effect. I hated the first game, loved the second game (haven't played the third game). Namely, I didn't like how the levels were offered in the first game. I think I picked the level with the Matriarch boss battle in it first, and got my ass handed to me again and again and again. I practically had to exploit glitches to get past it. I also felt like I never fleshed out any meaningful relationship with the crewmates. They were just there. I hardly ever touched planet exploration, and when I did, it seemed annoying and pointless. Leveling seemed daunting and impossible and my character never got particularly well powered by the end.
In Mass Effect 2, each crewmate had their own individual mission and achievement. One had to put effort in to get them to "like" you so they'd survive the last mission. Playing as renegade made it a lot more fun, too, since I had tried to be paragon in the first and it was boring. Mining planets for resources sort of had a point, and unlike the rest of the internet, I enjoyed it. I liked the story more, the graphics more, and the settings more. I picked a class I liked and by the end of the game, my character could do some cool shit. Yahtzee described it as a "gelatinous cube of gameplay" and I think that's what I liked about it.