Halo 3/Reach/ODST/4 playerbase as of now, 2019

While the games on the Xbox 360 aren't dead, the populations are quite low. It may be tough to find matches, especially for certain playlists. If you really do want to find decently populated playlists, then I agree with the others who have suggested
picking up an Xbox One and purchasing The Master Chief Collection. If you have the patience, then may I suggest waiting for
The Master Chief Collection to be released on PC, surely it'll have a decent population at launch.

I really appreciate you want me to go wait for MCC for release (I actually have both a good PC and a Steam account and good economy), but i really think the best way to appreciate Halo is on the ol' trusty Xbox 360.

But thanks for your answers, i'lll still go for the console!

Word is, the game should be out for PC around fall/winter holidays. If you're in the Halo Insiders Program you can get invites to alpha and beta testings.

I am a seriously PC Master Race player since i've spent a childhood having my bros not allowing me to play consoles, and since now i have a steady job income (And let's not forget a college career, to balance myself), i finally got into the plan of buying
my own Xbox 360 to play those Xbox-exclusive games i've been "watching from afar" since 2010. I was seriously thinking into inmersing myself into the Halo series as a start, but i was told it's playerbase/fanbase isn't the same as before (I am talking about
before 2010 or so, considering that the console got released on 2006 or 2007). I've been constantly watching some Halo 3 machinimas VERY MUCH and i actually once got invited to be an extra in one by a lucky friend that had the console and a clan, but had to
reject it since Xbox WAS NOT in my budget at that time (I was a teenager at that era, living under my parents' income).

Is Halo 3, or Reach or ODST or 4 still played nowdays? I know that Xbox One is the predominant console when talking about Xbox, but i was actually wondering if these games aren't dead already (Online, i mean).

Just get an xbox 1 and the mastercheif colectoin

I agree with the others here. If it's within your budget, i would consider getting the master chief collection on the Xbox one. If not, the mcc will be available on pc shortly, so if you'd like to stick to your roots, that's certainly an option. Besides,
once this happens the playerbase will surely surge, so the later may be the better option for you.