Super Mario Bros.: Made me a Nintendo fan for life. Back when I saw it for the first time (probably some time early in '88), I was blown away. It was far beyond anything I had seen at that point. The level designs that actually teach you how to play the game without beating you over the head with tutorials or in-game messages, the enemy variety, the music, and the tight controls made for an amazing game. After playing it, I had to have an NES of my own, and I finally got one as a Christmas gift in 1988. I was all Nintendo, all the time back then, and Super Mario games were my favorites.

Mega Man: An incredibly fun game, one that when it started getting sequels I had to play them. Mega Man quickly became possibly my favorite series not named "Super Mario" at the time, and still ranks among my Top 3 series ever, and my #1 favorite third-party franchise. I still replay those old 8-bit Mega Man games on the regular. They offer a solid but fair challenge and it only takes me like an hour or so at most to beat one, so it's easy to just crank one up and replay it, or just spend an afternoon doing a marathon of several of them.

Final Fantasy IV: I was engrossed by the story, setting, and music. It was the title that showed me that video games could have deep narratives as well as characters who actually change and grow over the course of the story it was telling. It also showed me that RPG games didn't need enforced level grinding once the worlds got big enough.

Super Mario 64: What the original SMB did for 2D platformers, SM64 did for 3D platformers. The switch from 2D to 3D was a rough one for video games as it was largely uncharted territory at that point. But in a time where bad cameras and terrible controls were probably the norm rather than the exception, Mario 64 comes along and shows that a 3D platformer can have impeccable controls and a decent camera. I wasn't a huge fan of most early 3D games, but Super Mario 64 showed me that good 3D games could be done. It probably also helps that Nintendo understood the importance of having an analog stick on the standard gamepad that comes with the system, and designed the N64 controller explicitly for games like Mario 64.

Halo: Combat Evolved: It was the first game released in my adult life that engrossed me in the same way those earlier games I listed engrossed me. Amazing controls, fun encounters, well-integrated vehicular combat, an amazing soundtrack, and levels that were more than just the (often maze-like) corridor crawls that defined most earlier FPS titles made this an instant classic for me. Once we all got Xboxes of our own, a group of friends and I would get together semi-regularly to have LAN parties, which was to me still the most fun I've ever had playing a multiplayer game. I still play the campaign all the time, and it's to this day it's still not only my favorite FPS title ever but my favorite non-Nintendo game ever. The only games I'd rank above it for my all-time favorites are Super Mario Bros. 3 and Super Mario 64.

On the SimCity thing, it’s impossible to understate how huge the concept was. And it’s affected a lot of games outside of the city sim genre. Any game where you build settlements, like Fallout 4, was influenced by Maxis.

Yeah - Tycoons, God games, even Harvest Moon, to something like Factorio...can all be traced back to SimCity.

It also proved to game publishers that "software toys" that don't have end goal can make money.