I am looking for a good NES emulator for latest versions of ubuntu. Any recommendation?

Please do some basic research before asking a question.
Literally your thread title in a search engine.
I have DesMuMe, Retroarch and Dolphin emulator installed. I'm pretty sure at least 2 of them do NES.

I made more than "basic research" before asking, I am not stupid. As I said, I ask for "recommendation" because the ones I found weren't satisfactory. As far as I know it is not mandatory to answer so if you do not like the question just let it go.

Thanks anyway

All you will get are suggestions. Ultimately satisfactory is in the eye of the beholder. One may like one while another hates it. The only real way is to try them till you find the one you want. If you are looking for certain features then that would help narrow it down.

Try fceux or nestopia.

You are right, it is not mandatory to answer, and also it is not mandatory to explain what are you looking for. But without details you will get no acceptable answers. So please explain what's wrong with those apps, why do you need another one?

Thanks anyway

It's been a few years since I was into emulators, but last time I checked it was RetroArch with the Mesen core.

With the second place going to RetroArch with the Nestopia core.

I have tried FCEUX but problem with this is that when you maximize, most of the window is black. The method to scale it up is not well programmed. When you close it and reopen it, it doesn’t remember some settings.
I used to run FCEUX under Windows and the Windows version was good.

I think I tried some others under Linux and they also sucked.

So, under Linux, I use RetroArch. I downloaded it via Steam.
This one supports many platforms which they call cores. The Mesen core and another one supports NES.
I have not tried it but I have tried Mesen-S which emulates the Super Nintendo.

I find RetroArch weird. It is fullscreen. There doesn’t seem to be a way to put it into window mode.
Once you load a core, you can then open your bin or bom or whatever game file. Again, this is annoying. Each time, you have to surf your directory structure to find your game file. Why can’t RetroArch remember?
Other apps, such as KolourPaint and LibreOffice can remember. My own apps can remember. That’s because I programmed it to remember and store the program state in Config.ini. Programs have been doing this since Windows 3.1.

Next annoying thing, when you start your game, the main window closes and creates a new window to run your game. Again, it is full screen.
To quit, you have to press Esc twice.
But where did RetroArch go? It closed itself? Oh man!
I have to reopen RetroArch each time I quit a game?

Other than that, the GUI of RetroArch looks polished.

Is RetroArch the best under Linux? I don’t know.

I think you're supposed to make RetroArch "playlists".

Fceux is considered a good NES emulator for the latest versions of Ubuntu. It offers good compatibility, accurate emulation and debugging features. Other options include Nestopia and Mednafen. Ultimately, the choice depends on your personal preferences and what features you're looking for in an emulator. For More Visit Now