Hero Chat

Kenny, Chaos Heavy Bolters require both an armory and Tier 2.
Chaos is playing around with them on Tier 1 (I think they stopped doing that in Space Crusade).
ValgallaWolf, if you have Space Crusade, maybe we can play in a couple of weeks. We can play over Hamachi - no key is needed.
Teng, here are my comments as (dare I say it) a pretty good player online.
Chaos Marines - yes, they are good in many ways: thick dreadnoughts, Hell Vortex with speeders, Marines themselves, Thermos...
and the Fast Tier 2 and Grey Knights + Chaplains combo is one of the most overpowered, very difficult for some races to counter.
Chaos - you're wrong here, Tier 3 is what poses the main threat. Among the units: terrible Possessed and Obliterators, Demon Prince (well, they rarely build him), Predators (and they always build them), and Invisible Havocs (funny, they can stun the enemy and the enemy won't deploy detectors).
Tier 2 is so-so, everyone has probably learned how to counter the Mass Zerks + Sorcerer combo.
da orks are made for fightin' n' winnin', 'ummie.
Tier 1 - Uber Mek with Uber Teleport and Jokers. What else do you need for happiness? After the Cannon Rush - Big Shootas with insane damage and no setup time, like Heavy Bolters. Stormboyz with Sergeant and upgrade to Claws - Big Boss, Lootas, and Generators.
Wartrakks - good, Nobz - even better. Claws are only given to them in Tier 3, but even without them, they are still very strong.
Tier 3 - generally one of the strongest. Free Sluggas are just devastating. And Gitz with Doc and Bombs.
Eldar - no comment, Dragons, early units, Reapers, Falcons, Rangers, Spiders...
...but teleportation and invisible buildings are just a gimmick. The Eldar army is already very strong. I'd rather move to Tier 2 earlier than research something in the gate.
Imperial Guard - they are definitely unique. I can say one thing - their Tier 3 and Tier 2 are just great. Tier 2 is probably the best. Guard, Executioners, Priests, Sentinels, Hellhounds. These are very weighty "arguments".
Chaos - I've already said... overpowered, overpowered...
Tau - pure overpowered. Drones, Fire Warriors, Crisis Suits with Flamers, Barrage...
That's how it is.
P.S. ValgallaWolf, come on, I just expressed my opinion, nothing personal. Apparently, everyone will stick to their own.

Added 15 minutes ago
P.S. Why like flies?
"Remember! The Guardsman is tough and hard to kill with a Priest and Commissar behind him!" (c)
...in general, I play Imperial Guard most often for several reasons.
1) They spread the Word of the Emperor;
2) It's very difficult to play as them, and I like that - that's why I constantly play as Infamous in Fifth Edition. There's not much interesting in defeating the enemy with overpowered units.
3) This follows from point 2 - a lot of fun. And I'm drawn to that. I was just born that way - I prefer fun to grinding:)
4) Also from point 2 - a very interesting aspect.
5) Style. Probably the most important thing. As someone wrote somewhere sometime? (not about Dawn of War, but in general)
"Why the Guard? They have no high technology, no genetically enhanced muscles, their claws and teeth cannot tear through tank armor, their bodies are not filled with the energy of dark gods. They have only a rifle and a prayer to the Emperor. They fight the most terrible and disgusting creatures in the galaxy, at the cost of their noble lives, defending their people and their home. They can only call upon the Emperor for help, but they must rely only on their own valor and courage."
That's it. That's my main reason...