1. Elf Rogue - I wanted to play a rogue ever since our 4 year campaign set in 3e and never got the chance to. So this was the first class I played when 4e came out. Result: Lvl 4 and still living. We played 4 or 5 sessions and then our DM up and quit the group and moved 2 hours away to a bigger city. Campaign over.
2. Half-Orc Barbarian - In 3e, I was deathly afraid of melee combat because of all the save or dies that our campaigns entailed. After playing the above rogue for several months, I was hooked on melee action in 4e. I wanted to dish the dmg so I started with a Dwarven charging Fighter for 1 session until PHB2 and the Barbarian came out. I switched and instantly loved the DPR it could dish out. Result: Lvl 9 and still living. We had issues with 2 group members and canceled the campaign after 8 months.
3. Dwarf Cleric - Following my love of melee in 4e, I still wanted to try to play a healer and this Cleric fit the bill. I tried the caster version for a session but hated it. Result: Lvl 9 and still living. We played 3 or 4 sessions and then I convinced everybody to play LFR.
4. Githzerai Monk - Melee trend continues with the launch of the PHB3. The Monk looked amazing for BF movement abilities and he hasn't disappointed. I play him in our at-home LFR campaign. Result: Lvl 4 and still alive. We've played nearly 10 adventures over the last several months and are putting the campaign on hold to pursue Dark Sun.
5. Warforged Warden and his owner an Eladrin Wizard - 2 other friends and I are doing the season 1 encounters on our own. 1 guy is DM'ing while 2 of us are playing 2 characters each to fill out a party. I've never played a defender and the Warden seemed awesome given his burst marking ability and saving throw at the start of the turn. He's been one of my favorite classes to play so far and I will consider playing him longer. I'm not a fan of living constructs...but I came up with a backstory I'm happy with so I'm enjoying the Warforged. Eladrin Wizard on the other hand is quite boring and I'm swapping him out for a Halfing Sorcerer. I played an Evocation Wizard in 3.5 and absolutely loved the devastation and destruction he caused. I was hoping to make a 4e "battle wizard", but it's not to my liking. Result: Lvl 3 each and still kicking. We just finished encounter 3 and are still going strong every other week. Warforged Warden gets 5 outta 5 stars, Eladrin Wizard gets 2 outta 5 stars. Sorry WotC, but I hate the new Magic Missile. Just standing there and dealing X points of dmg per turn sucks IMO. Halfling Sorcerer will be played next session.
6. Shardmind Shaman - I want to revist the leader role for our new DS campaign starting next month. I have problems staying focused at the table during other people's turns and so I thought playing the Shaman would help me stay focused because of the need to manage my Spirit Campanion every turn. I'm looking forward to playing a ranged leader class. We'll see how it goes. Result: Lvl 1 and starting in a month or so.
Race choices...I prefer to match up primary stats as I like getting the most bang for my buck. However, a solid racial power suits my purposes more than stats do and so I chose most of my races to work with the class I was choosing. I despise being a boring human (since I'm a boring human every day of my real life). Other races just bring something different and fun to the table so I will try to avoid playing a human as best as I can for all of 4e.
And there you have it. All the classes and races I played and a snippet on why I played them.