Planetside... I'll share my experience with you :3This game when I first played it, was awsome, I loved every second of it, there was slight rpg style element where you gain battle exp to gain access to all sorts of arsnal and vehicle's which is fun, but best of all is getting into the heat of the firefight!
The Adrenaline you get when joining a huge assult on a base, by air on the huge transport carrier with your squad as you hover directly over the enemy base... the ground is riddled with explosions, tanks and chaos, suddenly the pilot cries out BAIL! BAIL! you and your squad jump from the ship, jetboots light up supressing your decent as you land on the base roof for an overwhelming assult! Heavy assult armed with your side's personal weapon like jackhammer for new conglo you can tear apart anything to your advantage due to the close corridors or if you're a MAX you'll make dust out of any enemy lacking decent armour. You or one of your squad members is hacking the Control Console it will take 15mins to fully hack so you must be protected or protect the cc from being rehacked
by now the enemy is desperate to regain control, floods of armour running towards your location and you're already low on health but you will do everything to buy more time eventually you'll be taken down
exciting
Being assult has its fun side but nothing beats being a stealth recon/assassin
you have no armour whatso ever but you cant be seen easily, like preditor in the movie, except everytime you move you glow slighty revealing yourself. So running towards a base cloaked, you notice a dot moving in the distance so you'll follow it, lo an behold! an enemy sniper finding a suitable spot to hide hehe you sneak up behind him with all the ninja training you've had, walk a bit run a little keeping a good distance and stopping when the target stops >
you pull out your pistol, move closer and behind the target then pull the trigger bam! you just assasinated someone > 
lol had soo much fun for 2-3 weeks then it hit me, im assulting the same style base which has no revelent use whats so ever, when the base is taken over what now? everyone moves onto the next, then it repeats again and again. There wasnt any reason to stay and defend once you've beaten the enemy back. There isnt any glory and ive felt empty, no reward, no satifaction just trudge on. :/ It got boring and I didnt even finish the month, sure the battle is fun but it lacked a reason for me to continue and thus it ends. woa that was long lol
I don't play Everquest as I find it too much to take in, its more for hardcore players too much rules and detail.
I have played Asheron's call2 which was good fun for a month or two, I've been playing Ragnarok since it was in alpha stage (same as bugs :3) and Im still on it from time to time.
CounterStrike is good an always will be, just have to be aware that there are cheaters around.