OK, as soon as I saw the bounty I couldn't resist.

Best FPS ever for me is Unreal Tournament (I, II, III, IV), for the following reasons:

1. Super fluid and efficient graphic engine: Unreal Engine, still used today btw, reached version 5

2. Variety of weapons: long range, medium range, melee, rockets, grenades, energy weapons with the possibility of creating combos (see plasma rifle)

3. Various gameplay for single and multi player: deathmatch, team deathmatch, capture the flag, assault, instagib

4. Possibility of using vehicles on latest versions of the game

5. Great maps and scenarious

6. Maps editor for players

7. Great mobility: dodging, dodging on walls, jump boosters, sliding on surfaces

8. Great e-sport competitions all around the world

9. Possibility of giving orders and commands to bot team members

10. Great futuristic-dystopian atmosphere

As a beginner in content creation I have noticed so far that:

1. You can't afford to be mediocre, content out there is so much that you always have to aspire to do something great, aim for the stars;

2. Sometimes is better to put aside your schedule and "go with the flow", publishing content about something that is actually interesting for the audience here and now;

3. Consistency: publishing at a regular pace and on a specific time of the day/week/month helps being fresh and present in search engines;

4. Learning to manage multiple social accounts can help you being discovered faster;

5. Don't push it too much: audience can detect if you're doing your content out of passion or spamming and throwing stuff out there just for monetization; passion gets you further.