Halo Wars and Halo 2 are the most epic games if all time. OF ALL TIME. Halo 2's storyline, campaign, and graphics are breathtaking. Halo Wars's graphics, storyline, and graphics are breathtaking as well. No game will EVER come close to Halo 2 and Halo Wars.
Wut? Halo 2 was a great game, I give it that, but its Story wasnt nearly as good as CE's. The campaign was fun, and the Graphics were decent, but its one of my least favourite Halo games. The ONLY thing I can say about Halo Wars is that the story was great, and fit in well with the Canon, while the Cutscene graphics were amazing. The MP was meh, because every person used the same tactic, and the Campaign gameplay was again, meh. My two favourites are C.E and Halo 3. C.E for its incredible story and good times, and Halo 3 just because of its good times. I had so much fun just playing custom games with my friends, so many good memories were made.
halo 2 was best. for all the reasons ninja arbiter said and you canz play arby level. and the only real boss fight that wasnt easy as hell. halo 3's boss(guitly spark 343) was ok but halo 2's was better.
Halo 3: ODST Only because it's storyline was brilliant. The only downsides were there was no matchmaking support whatsoever and firefight took forever to load up.
I think the Boss Battles were stupid personally. They just weren't Halo. To be honest Halo 2 is one of the worst of the proper Halo games (I don't consider Halo Wars a proper Halo game), in my opinion. Also, Guitly Spark? Lolwut? Again, I didn't enjoy Halo 2 as much as Halo: CE, ODST or Reach in terms of campaign. I thought it was better than Halo 3's though. I never played the multiplayer with online so I don't know what to say about that. Halo Wars is better than some people give it credit for but it's still not a top-notch game. The campaign wasn't great, gameplay wise, but it did have beautiful cut-scenes. I got bored of it in less than a week and all I really enjoyed doing on it was playing that Quick play thing. Also Halo 2's Graphics were breathtaking.
The truth is, I like all of the Halo Games. But if I had to pick, it would be Reach. Halo 2 would come in a close second though, as the Multiplayer in that game was phenomenal. Reach's excessive amount of features is amazing. Also, having the ability to customize your armor is awesome.
No competition, it's Halo 2 all the way. How can you argue with maps like Headlong, Containment, and Lockout? Plus, unlike Reach, it actually had a campaign worth playing. Not to mention it had the BR and Master Chief, two of the best things in video game history. All Halo: Reach has to brag about is forge and the fact that the game proves that Halo is STILL miles better than COD. (EDIT - Nevermind this, Reach has now trailed lower than CoD.) Plus, Jun and Kat are keeping me from ever wanting to complete the entire campaign. How did Bungie manage to make two characters that annoying? The world may never know...