In keeping with the nostalgic theme, I did a quick internet search to see what’s out there. One of the most interesting and most effective way to run all the classic games natively is through an open-source DOS version called FreeDOS. You can download the system from their site (link below) and then you’ll have to boot your PC from it and then be able to play the original DOS games with full valour. However, it’s also most geeky way to do it and certainly not recommended for most gamers.
Other sites provide online gaming experience, through a browser…via Flash plug-in, JS app, or HTML5 webapp. My search didn’t yield any strong recommendation however. Granted that I didn’t spend much time on trying each one or digging deeper; but my initial feedback is: BE CAREFUL! I’m not recommending any of these, nor am I NOT recommending.
I found that many such sites are riddled with ads and other distractions. Confusing re-directs to other pages that makes you think you’ll need to download something else to play the game, etc. Click-bate? Beware downloading anything directly into your device. Play online or emulated online versions only when possible. In the end, you’re on your own.
Click on the images below to explore the sites…
FreeDOS: 
ArcadeSpot: 
Atari Vault: 
Emulator Online: 
Free80sArcade: 
PlayRetroGames: 
Side-note: I prefer the real tactile experience with some of the arcade games, the way they were meant to be played. To that end, the classic NES system is a good choice. Revamped to be half the size, the system comes with 30 classic games, and it interfaces to your TV via a HDMI cable (included). The classic controller and its cable (3′ I think) comes bundled too. 
If you’re interested, check out Nintendo’s page for details and do your research according to your TV size and distance you need to play. There are after-market mods of the controllers to be also wireless. When this refurbished version first came out, they sold out all units and sold in eBay for 3x the original price. I hear they’ve re-stocked.
If you do find a great site, please do share in the comment section.
