"Console wars" have occurred across all generations of console gaming, but typically the most well known use of this phrase is from the 16-bit era of gaming. TVTropes calls this the 'classic battle.'
During this time, Sega and Nintendo both aggressively marketed their systems, with many Sega ads directly attacking Nintendo, trying to paint the SNES as an inferior system for casuals and kids. This was generally unheard of at the time - Japanese companies found it inappropriate to do competitive advertising prior to this campaign.
In the autumn of 1990, Kalinske took over as CEO of Sega of America, and instantly began work on consolidating the new philosophy: that the Genesis was the machine that kids graduated to when they found the NES too limiting. “The starting point,” says Kalinske, “was that Nintendo was clearly the preference of the child gamer. To me, it seemed logical to really hammer the older audience, and to do that with more aggressive marketing, and with sports, strategy and role-playing games that appealed to teenagers and college-age males.”
At the time, I remember kids arguing about which system was superior, and you had to be able to defend the one you had, even though buying a console as a kid was basically impossible. You had whatever your parents had/could afford/were willing to buy you :)
Generally speaking, though, "console wars" occur every generation. Each console vendor wants you to buy into their walled garden and purchase their software exclusively. They take steps to keep certain games only available for their platforms, and they use aggressive marketing to make their console seem like the most desirable one.
Technically, there have been console wars as soon as the first Pong clone appeared. However, the SNES/Genesis era really defined the term, and the advent of the internet made these types of arguments far more prevalent.
By definition of "Console" to mean a system dedicated to play games or entertainment software, it depends on the criteria. In basic format - yes.
From Wikipedia - Screensaver, History:
(emphasis, mine)
The Atari 400 and 800's screens would also go through random
screensaver-like color changes if they were left inactive for too
long. The user had no control over this. These computers, released in
1979, are technically earlier "screen savers." And prior to these
computers, the 1977 Atari VCS/2600 gaming console included color
cycling in games like Combat or Breakout, in order to prevent burn-in
of game images to 1970s-era televisions
Though the "Brown Box" is considered to be the very first home console in 1967, it did not reportedly feature a screensaver and screensavers were primarily used on early computers with CRT monitors. As written in the snippet above, the Atari 2600 had a screensaver but it should be noted that only if the ROM included it - that is, "screensaving" was contingent on the medium and the programming of the medium.
As far as my own research, consoles required a cartridge or disc inserted to boot and function or had the ROM(s) permanently attached to the internal PCB until the Sega Saturn.
Many other consoles including the Nintendo Entertainment System to the 3DO Real Interactive Player and Amiga CD 32 did feature animations asking for players to insert a medium, which can also be argued as a screensaver on a functional level but served more as a mechanic to prompt the user to act.
This means Sega Saturn was the first home console that would boot without a medium inserted(*)(**) from and allow the player to use other preinstalled device features (such as playing media and manipulating storage devices).
Incidentally, playing music on the Sega Saturn featured a flying spaceship as a form of screensaver, which is the truest form of screensaver that was built into a mechanic of the console rather than of the medium.
Therefore it can be argued that while the Atari 2600 was the first console to use a screensaver as a feature of select media, Sega Saturn was the first to deploy it as a standard function of a feature.
There is a YouTube video showing the start-up screens of every major and most minor consoles from 1985-2013 to see how some consoles had iterations of what one may consider a screensaver until the user took action. It's run-time is just over 14 minutes.
(*) Sega CD was an accessory to the Sega Genesis released in 1991, not a separate console developed to operate independent of something else therefore not relevant in context to the question or scope of answer.
(**) Sony PlayStation was released in Japan on December 3, 1994 - 11 days after the Sega Saturn in their country of origin.
Best Answer
It's pretty hazy by what you define as a user interface. Judging by the criteria you laid out in the comments then the Sega Saturn (1994) is the first console to have a home dashboard with various options including playing games, music, and console settings.
User Timmy Jim was correct, stating:
User Fana also pointed out:
Before this, the earliest main menu I could find was the Sega CD (1991), but that shows only a Press Start which does not meet your criteria.
Earlier gaming devices were not consoles but actual computers such as the Apple II (1977) and the Commodore 64 (1982) but did accept inputs to start games. Neither of these are 'video game consoles' and thus do not fit your criteria.
A notable console is the Atari 2600 (1977) for having the first screensaver. While this could hardly be considered an interactive dashboard, it would turn on after a period of inactivity, change colors to prevent screen burn-in, and would turn off after user input. If we're playing loose with definitions, this is the first menu of any kind on a dedicated gaming console.