Between 1-shots and two currently running campaigns, I realized we've played the bulk of the 4E character classes. Here's some of my thoughts to spur any discussion, all representing heroic tier.
Battlerager - Generates temps on a hit, on a miss, regenerates and couple with a dwarf, hits like a truck and surges for absolutely absurd values. AC is totally unimportant. Conditions are the only thing that slow this class down in a fight. Makes other defenders look like paper dolls and our strikers cry. Will never allow in my games again.
Wizard - In the hands of a creative player, awesome. Otherwise, tends to suffer from being from the PHB and not being as well balanced as the classes that have come out since then. The costs of rituals turns one of their key abilities into a gold dump. I've been considering ways to give this class a little help.
Bard - A really well-designed class. Thematically works great, lots of neat abilities. Probably our favorite thus far.
Barbarian - I'm not impressed but when the rolls line up in the character's favor, I've seen the barbarian do some absurd things. Problem is that it happens so rarely and the barbarian striker is overshadowed by the defender battlerager in every battle.
Cunning Rogue - Works well with the bard to move people around, good sustainable damage. Obtaining CA isn't difficult at all with a little thought. Best power to date? "Go For the Eyes!" I laughed myself silly.
Assault Swordmage - Another well-designed class and a lot of fun in the hands of a creative player. Can really screw with the enemies, get free attacks, and put on the hurt. Tough as well with a great AC. Puts the "D" in defender.
Cha Paladin - Be very careful with builds. Pallys still suffer from MAD (multiple attribute deficiency). Our straight Cha pally was a radiant/vulnerability build and it was NASTY. Tough, sticky, and could lay the hurt down. Also could heal. Was a lot of fun. Other builds I'm not so sure about.
Dragon Sorcerer - Player was able to optimize gear for some absurd at-will damage. This class really can put the hurt on. Only saw briefly so not sure if they were a one-trick pony, but you can't argue with the results.
Monk - Also only saw briefly but I really like the PHB3 mechanics. Thematically it doesn't blow my skirt up but mechanically the ability to essentially have two uses (std and movement) for every power is a cool wrinkle. Watched the monk take down 3 non-minions in one attack.
Night Stalker Assassin - One of the least damaging strikers (on average) but they make up for it with some terrific abilities. The at-will teleport is absolute clutch and the ki focus is very handy as well, if you can get one. The controller HP makes them a glass cannon. Setting up shrouds is a little fussy. Subs in for a rogue very well.
Warden - As a primary defender I'm not impressed but they have some very neat abilities. Seem to come into their own a bit later. Not really that tough but can generate some temps or self-healing. Player seems to like it but I'd never play one.
Invoker - Player seems to like it but has a very specific build based on thunder powers and at-wills. Outside of that, doesn't do a whole lot. Not a bad class per se, just not very interesting. Plays more like a weak striker than a controller.
Stalker Shaman - We've all been really impressed by this class. A great mix of offense, blocking (via spirit), and healing. One of our well-rounded characters that always seems to be able to contribute in nearly any situation.