I am thinking of getting an original NES and I noticed there's two versions...
The top loader is normally slightly cheaper on ebay although not always...
basically I'm not 100% clear on whether the differences are acute for anything other than method and I didn't see
a discussion on this topic here so I thought I'd start a topic...
Basically I'm leaning towards whichever is cheaper wondering if there's any serious issue with that idea.
The original NES has composite output, which will have better quality and hook up to a modern TV more easily.
The top loader only has RF output, which will connect to channel 3 through your TV's cable input. This has muffled sound, and may be a bit of a pain to set up with a modern TV.
There was an AV Famicom top loader with composite output, but it was a rare Japanese exclusive thing.
You could mod the top loader for composite output (just like a non-AV Famicom can be). There are also RGB and HDMI output mods that can be installed, at which point it wouldn't matter what the original outputs were.
The other main difference is that the top loader has no lockout chip, and a nicer slot connector. The connector on the original NES is easy to replace, though, and its lockout chip can be disabled with a very easy to perform mod. (I personally recommend the "blinking light win" slot connector replacement.)
More minor difference is the lack of an expansion port on the bottom, but no games ever used this. Some homebrew might someday, but it's a little pie in the sky.
Personally I prefer the original. It looks nicer and has more features as rainwarrior mentioned. The downside is you have to clean your carts and connector to not have issues getting the games to boot. Once cleaned it usually works fine. I even modded my original connector to have less grip on the cartridge so as to make insertion easier and having less wear on the cartridges. Works fine and boots almost every time as long as the carts are cleaned with a magic eraser and/or isopropanol alcohol.
Then there's also that about expansion audio mods working differently on the top loader. And there was the unofficial device ENIO that uses the expansion port, but I'm not sure if it's being sold anymore. Also a keyboard+mouse adapter like
this would probably also need the NES expansion port if it was built.
The AV Famicom is also an inferior model as it's missing the microphone. It has NES-style controller ports but you need to mod them to support some NES accessories like the Zapper and paddles as it's missing some pins.
If I get a NES someday it will be a SCN PAL original front loader and maybe a Blinking Light Win. BTW can you play Nintendo World Championships with a BLW?
I'm surprised you're able to get a top loader cheaper. It's absolutely the preferred model, but the downside is of course than at least a composite video mod is a must. But then again, you could easily argue than an RGB mod is a must for both models.
I've modified a USA toploader in order to get AV out, it's quite easy to do. This has become useless since I then bought a top loading Famicom anyway, which is the "definitive" version of the console in many ways : Compatible with western controllers but also dogbone controllers, has SNES-compatible output, and is really pretty design. Since my USA toploader has become basically useless I could even consider selling it.
I'm surprised toloader would be cheaper, normally it should be the opposite, not only the design is prettier but also does not come with the connector issues the fronloader has. The fronloader is much more common too.
All Famicom's are top loading. The model with dogbone controllers is the AV Famicom I was talking about which is missing the microphone, which is even required by some games, so not the "definitive" version at all IMHO, although it is a very popular model. I prefer an AV-moded red & white Famicom (just not too old or it will be missing the looped noise feature which is a must).
The RGB-mod also have some incompatibilities so I'm very suspicious towards that as well.