Old cartridges with their ROM memory - out of everything, they should probably last the longest, until we finally get to see something like 5D optical storage or some other advanced tech,

Can confirm, I own Atari 2600 carts from the 1970s that still function. Heck, as a kid I had a copy of Yoshi's Story on the N64 where the casing had been smashed in, but it still worked.

Optical discs by contrast are easily scratched and most from that long ago don't work any more.

Ps2 and under since all data is on dics

If someone told me back in 80s that we still won't have crystal based (or something similar that was in the realm of SciFi back then) storage in 3rd decade of 21st century, and that cartridges from early console gens would still be the best (if not most cost effective) way to deliver games, I would probably think they were crazy - yet here we are.

Cartridges. Not flash ROM cards like in Switch, but cartridges, esp SEGA Genesis. I like the clamshell case. The small size and shape. Carts had no load times generally. Durable. Those things are 30-plus years old been through hell, and generally still work.

When I use to do Physical media - it wasnt the format of the physical media (cartridge, CD, etc) but how it was presented or put together that got me to say it was my favorite.


PS1

The PS1 glass cases were awesome.

I would say (4K) Blu-ray since all the data of modern games can fit on there, but ever since cases got flimsy with just a disc and nothing else, PS2 / GC / XBox / Wii(U) CD/DVD are my favourite. Sturdy boxes with art work and manual inside. CD also had the benefit you could play the game music in any CD player from track 2, eg Wipeout 2097 is a great music album as well.

Early 360 and PS3 were still good as well but not always the complete game on there and the decline of the manual and extras started there. Plus blu-ray boxes (ps3) feel flimsy and Sony changed the side labeling halfway through doh!

Cartridges were great for convenience but hard to organize on a shelf and the Switch cartridges are so tiny you never find them back if you don't put them back in their flimsy case. 

Old snapshot of some of my games

I don't collect physical anymore, but my favorite (and I am a Nintendo guy), but I loved Genesis. Loved the plastic cases, manuals in the case, cart nice and secure. Great artwork, side labels, etc. Genesis had great physical games.

Cartridges. Discs are great but are a bit of a pain to maintain. If you let the humidity in your house get over 80% your discs will be at serious risk of rotting over 30 years. But if you keep things at 50% humidity and 72 F then discs have been shown to last over 100 years. If you live in a humid climate get ready to run a dehumidifier every summer for decades. 

I think a lot of discs have lasted just because most beloved game discs are only 30 years old or younger. But long term you need to be a climate control freak. 60 years of 80% humidity summers will rot your discs. And a decade of having no HVAC at all will almost certainly trash your discs. You can't go from 60 F to 90 F and equally wild humidity swings and not have disk rot. This is why so many UK Saturn collectors have found their collections decimated. 

Thankfully the bulk of my disc collection comes from Arizona where it is bone dry almost year round so I have zero rot. I live in Iowa now but keep that dehumidifier running nonstop during summer. 

Cartridges. Particularly GBA ones. I really like the look of them and the size feels right.

They do drive me slightly mad thought. Some games have battery powered save versions and EEPROM versions. And whoch sticker numbers correspond to which versions is something that bafflingly has quite little info online.