Super Mario Bros.

Beyond its impact or importance to the industry, is a game that I still can pick up any day, play it to completion and have an absolute blast with it. Is one of the most pure fun games out there for me, never gets old, lost count of how many times I have finished it.

Personal favourite: ELITE - open world in space, 8 galaxies each with 256 planets, trading, pirating, missions, mining...Newtonian physics (albeit limited)...all that in 1984. For scifi geek, like myself, it was dream come through.

Most influential: probably Ultima (actually, arguably the most influential video game series of all time)

"Best": probably Pac-Man

Suspect was a wonderful game and my favorite of the Infocom originals.

Have you ever played any of the homemade Infocom-style text games made since then? There are a number of authors out there, but my favorite is a guy named Adam Cadre. His two standouts are Varicella (emphasis on the "interactive") and Photopia (emphasis on the "fiction"). Worth looking up.

I always wanted to get a bit more into Infocom. So now I put Suspect besides the Zork games and probably will look up that Cadre guy.

Some contenders:

1. Wizardry: One of the Ur-RPGs (released in 1981) and the biggest influence for JRPGs. Games like the Etrian Odyssey series are specifically styled as spiritual successor to Wizardy.

2. While we're at it, I'll also name Ultima IV, the other Origin series (ha!) of JRPGs. Almost all modern RPGs could be traced back to both Wizardy and Ultima in their influences (except Roguelikes, and even those often borrow some from Wizardy these days)

3. Colossal Cave/ADVENT/Adventure (It's known under all those names):
Play it!
With what? Your bare hands?
Yes!
Congratulations! You just beat the game with your bare hands! (unbelievable, isn't it?)

4. Super Mario Bros 3: This game really expanded the scope of Jump and runs massively past the originals of both Super Mario Bros and Pitfall. Much longer, much more secrets, overland map with multiple paths, the list goes on

5. King's Quest, specifically King's Quest III. Lucasarts really became good in the 90's with Monkey Island, Loom and Day of the Tentacle, Leisure Suit Laffer also really became good only with 5 and 6 in the 90's. But King's Quest was already great in the 80's and went the other way in the 90's...

My Top 5 in this order are:

1) Super Mario Bros 3 - Simply the greatest of the 80s - it's huge, has great graphics, great music and most importantly really fun. Some still say it's the best mario game ever.
2) Tetris - Super simple yet super addictive. Absolutely perfect in portable format for the GB.
3) Pac-Man - The most iconic game of the decade and still really fun to this day.
4) Legend of Zelda - Best adventure game of the 80s easily. Doesn't hold up brilliantly today but still a classic.
5) Phantasy Star - Best RPG of the decade ahead of the early FF games for me. Haven't played many from this era but I think this deserves its place.

I feel a little bad for not including any earlier classics that were in the on the Atari 2600 but the later 80s games that came out on the NES & Master System were simply more refined and had a lot more depth rather than the simple (but fun) arcade style games that came before.

Eh, it's got to be Super Mario Bros. 3 by W.O. Honestly, except for a few select titles, most games from the 80s are borderline unplayable nowadays since they're filled to the brim with artificial difficulty / rehashes to make short arcade experiences last weeks for the kids back then.

To me there is no real doubt: Super Mario Bros. 3. That game has so much charm and creativity. Extremely polished with a perfect level of difficulty. I still replay that game every few years and get immersed each time. I still love replaying Super Mario 64 as well, but with time the flaws have become more obvious (still a masterpiece though), Super Mario World doesn't do much for me anymore.
SMB3 is certainly the best 2D Mario game of all time, probably the greatest Mario game period, and a serious contender for greatest game of all time. Oh, and in contrast to popular belief, the NES version is the go-to version, not the SNES All-Star version. The 16-bit update completely ruined the charm of the 8-bit graphics.

The other 80's game that is an absolute masterpiece is of course Mega Man 2. They pretty much perfected the gameplay with that one. Certainly the best balanced in the series and the one with the greatest sound track, of any NES game really.

Some other strong contenders:
3. Ninja Gaiden
4. The Legend of Zelda
5. Super Mario Bros.
6. Galaga
7. Tetris
8. Donkey Kong
9. R.C. Pro-Am
10. Ms. Pacman

Super Mario Bros 3.