I definitely had the most fun playing H2 over the 3-4 years I did, but in terms of actual quality of gameplay, H1 is better IMHO. Sure it didn't support XBL, but it did support PC online play, which I had a good year and a half or so playing.
H3 vehicles - Yes they were way overpowered, but I disagree that they were for noobs only. Being able to carry your flag/bomb/oddball holding teammate on the wing of your hornet on avalanche, while being shot at by 8 BRs took skill.
I don't like how they "dumbed down" the vehicles in Reach. They are far too fragile. I can take out a ghost by myself and a banshee with 2 other DMRs within about 5 seconds. That is just plain ridiculous.
As much as I hate armor lock, it does have a niche, and that is for destroying/disabling vehicles. Other than that, it needs to be removed from
all 4v4 style gametypes.
Also that revenant thing was a poor addition to an already well established covenant vehicle arsenal. I'm even still on the fence about the falcon. An updated(
not upgraded) hornet would've been better I think. I also miss the elephant with a passion.