Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

You should be able to, ahem, find some convinent ROM collections on most torrent indexers. A standard NES game is only ~128kb, so the whole library of games is only like 750mb. It scales exponentially with every generation as data storage improved, so the SNES library is 2gb, the N64's is 5gb, and the PS3's is 20tb. I find that I really don't need the full library of a consoles releases available, so I usually only choose maybe a hundred or two that I'm interested in, there's only so much time in the day. If you don't need a handheld device I can recommend modding your ps3, it can emulate most anything, the hombrew scene is active and there's been a lot of support for it, plus for the majority of consoles it's a full custom firmware solution, so it's a pretty seemless experience once you set it up. Plus with the internal hdd there's plenty of space for stuff. Pretty much everything up to last gen is easily pirateable, so have fun with it, it's easy once you get the hang of it.

"Emulators & ROMs" part of megathread. Think it's not worth to buy something for the roms when you can donwload them. Why not get something modern like a steamdeck or ayaneo for a true handheld experience?

A raspberry pi or steam deck will offer a generally better emulation experience than a ps3- the homebrew scene for the ps3 leaves a lot to be desired.

Whatever alternative you're offered, I don't think it's worth spending more than $50 on an emulator console. (This is the maximum make sense price for any hardware that can emulate old consoles up to PS3).

If you want a handheld, Anbernic makes some good stuff. https://anbernic.com/ They do tend to load the SD card up with games beforehand, but the card is cheap & likely to fail, and the games are sorted & titled strangely (and may be otherwise dodgy). So you probably want to replace it with your own card with games you sourced yourself.

Loving my Ayn Odin. With little effort it will handle up to PS2 and will even handle some Wii and 3DS games. Form factor is comfortable. I'm really happy with the retro experience on it.

A raspberry Pi is a very good emulation device using the RetroPie image. A Pi 4b can go up to PSX/N64 fairly easily.

On the handheld side of things, most of them that "come with" ROM sets will have them loaded on an SD card. These manufacturers often skimp on the cards though, so expect it to die quickly. You can usually just clone the whole SD to a new one and it's fine.

Most of these devices use RetroArch and software emulation. However, there is another option. The Mister project and devices sold by Analogue use field programmable gate arrays - chips that can change their structure according to software. This means running an NES game on one of these devices is more literally like running it on original hardware. For accurate emulation, this is the best option by far. However, it comes with a significantly higher price tag.

In general the easiest and least expensive startup for emulation is on the PC. With fairly modest hardware, emulation of everything up to PS2 is possible with some newer platforms also being very emulatable (notably everything Nintendo puts out is easy to run because their architecture is largely straightforward, their systems are lower power, and there is significantly more demand for their games)

If you specifically want something hooked up to your TV, a first generation (launch window, before they increased the battery life) Switch can happily run a fair amount of stuff, including everything up to N64/PS1. The (new)3DS/2DS is also a great emulation device and can run basically everything up to SNES/Genesis handheld.

Oh and one more option. If you have Android, you can easily install a variety of emulators and use a Bluetooth or wired controller with them utilizing a controller phone mount.

I recommend the Chinese handhelds too, I only have a Retroid Pocket 2 (too old), Anbernic RG351V and a Miyoo Mini V2, I only use the RG and Miyoo, the later is great for simple games/quick burst but due the lack of wifi antenna it is not possible to use Retroachivements with it... which it is possible with the RG351V, also the Anbernic has quite the better hardware without a question.

Notice all these aforementioned handhelds would only give you a pleasant experience up to PS1 (minus Saturn), so if you want a handheld that can at least give you PSP, Dreamcast and N64 I'd pick an Android based Retroid Pocket 3+ Anbernic also have some capable models for this. it is worth to mention that if you have a relative new Android phone you already have a capable emulator with you all time, you'd only need a holder or a telescopic joystick to enjoy an almost endless library of games (despite having a PSP I finished Persona 3 Portable with my phone and a Razer Kishi controller).

A lot of it depends on what consoles you want to emulate. I'm no expert, but from what I've seen just casually looking through retro gaming forums, is that anything up to N64/PS3 is doable with relatively cheap hardware. But if you want to emulate N64 or PS3 and above properly, you're going to need to step up in specs.