Below, mostly everything else 😉

User warned -RavenXtra

1) Halo
2) Halo 2

Never played any other title of the series. =D

7. Halo 4 - a mediocre first try for 343, which has mismanaged the franchise past the point of no return. With boring, linear, and lazy level design; QTEs and scripted events; lackluster AI; and a mawkish story, the campaign in Halo 4 is a serious low point for the franchise. Multiplayer is no better. Ordnance and loadouts and a slew of other unnecessary "innovations" spoil the proceedings.

6. Halo 5: Guardians - sometimes it feels like 343 is comprised entirely of art directors and graphical engineers. Like Halo 4, Halo 5 looks amazing but it suffers in level design and AI, two essential parts of the Halo experience. Also, whose idea was it to play the majority of the game as the boring Osiris foursome, leaving Master Chief to the side? Thankfully multiplayer is much improved over 4, with the quasi-return of arena shooting. The coolest mp mode of the bunch - and 343's greatest gift to the Halo universe - is Warzone (although the microtransactions can bite me).

5. Halo 3: ODST - a significant departure from the traditional Halo formula that surprisingly works. The soundtrack is among Marty's best; the gunplay is as good as ever; and the Horde-esque Firefight mode is ridiculously fun and addictive.

4. Halo Reach - despite an insufferably slow start, the campaign in Reach ends amazingly, with some of the best open-area improvisational gunplay in the series. Multiplayer is ridiculously rich in modes and options, although let down somewhat by armor abilities.

3. Halo 3 - although its campaign felt a bit stiff and unoriginal, the multiplayer in Halo 3 is, arguably, the best of the series and best of the genre. Huge, meticulously designed levels with tons of modes, weapons, and matchmaking options.

2. Halo 2 - with two playable characters, more diverse locations, and a greater emphasis on vehicular combat, Halo 2 improved upon the original game in a number of ways. Multiplayer, although not exactly what Bungie wanted, was groundbreaking for home consoles.

1. Halo: Combat Evolved - the best Halo game. The best launch game. The best Xbox game. The best shooting game. The superlatives go on and on. With amazing graphics, controls, level design, storytelling, artificial intelligence, and, most importantly, tactical shoot outs, Halo stands today as a masterpiece, the game against which all other Halos are judged. Multiplayer was still in its infancy and not yet as customizable or deep as Halo 2 and 3, but it was still a lot of fun, particularly over LAN.

1) Halo 2
2) Halo CE
3) Halo Reach
4) Halo 3
5) Halo 5
6) Halo 4
7) Halo 3 ODST

Even though you had to buy another console to "finish the fight" or if you had it on the PC ... first you needed Vista to actually install it and secondly you never got to finish the fight, because 3 didn't come to the platform.

I mean 2 on it's own is great and it ends on a cliff hanger which amazingly breaks into the starts of both Halo 3 and Halo 3 ODST but still, as a standalone title it doesn't really do it for me where it left the series.

I only feel comfortable to rank the FPS games, haven't planer enough of Wars, Spartan Assault or Spartan Strike.

1. Halo 3: Everything that makes Halo a great experience exists in 3, I love almost every aspect of it.

2. Halo Reach: Only lacks in MP compared to 3, but the Forge, and campaign was stellar.

3. Halo 5: Say what you want about the campaign, it had some of the best moments of any Halo campaign to me. From Exhuberant (butchered) Witness' zoo to rusning down the Guardian and the set pieces were solid. The MP is top tier gameplay!

4. Halo 3 ODST: Best campaign, hands down, I love the noir tone. Best Firefight as well. 

5. Halo CE: This is mostly nostalgia for me, it's not that special anymore. But there are so many good memories from it.

6. Halo 2: Solid game, didn't play MP back then so I have no opinion on it.

7. Halo 4: It could have been great but it wasn't. Story was good but the campaign in general was boring and too static. MP had its moments but mostly it was just too different from Halo and too similar to any other FPS.

There, my ranking. It will be considered stupid to some because both of the 343 games weren't at the bottom but screw it :P