I've played tactical characters, warlords, strikers, defenders, but why mark an enemy and kill it in two rounds when you can just kill it in one and not need to mark it? Then you deprive it of retaliation. The main way to "win" D&D, not just 4e, is to take high value targets off the board as quickly as possible. Sure, a controller can help out with minions or what have you, but so can a ranger.
My comment about the best status condition being dead is not specific to 4th edition anyway, it's surprising people took offense to that. It's just that in 4e, with combats that often drone on into a grind, it's better to have more striking than less, and more optimal characters than less. Tactics are important, but the main one that applies in every game of D&D is teaming up against one enemy to take monsters off the board. Single target damage is where it's at. Spreading out damage is simply guaranteeing enemies live longer and thus get more rounds in which they can retaliate.
In the general case in 4th edition though, encounter powers should almost always be used very early in each encounter, or they should be retrained. The reason why is the same. The sooner you unload on enemies, the less of them there are, the less actions they can take against you. Meaning dead is the best status condition. That's the secret to "winning" D&D combat, if you knew what you were doing in 4e or other editions, while not playing a game of cat and mouse with your enemies, is to kill stuff faster instead of drag things out and let that enemy have another chance at a lucky crit.
It is from this perspective that I still say, I'd much rather two strikers at the front line than one striker and one defender. Two strikers means one bloodies a standard, the other kills it, in round one. Two rangers, for example, could take out 1-6 minions in the first round of combat. Or 1-2 standard monsters. A defender is going to take less damage, but deal a lot less. A striker's defenses aren't just his AC and HP, it's all the hits he didn't end up taking because he killed an enemy 1,2,3 rounds sooner than the defender could have. The difference in HP and AC between a well built striker and defender in no way accounts for the difference between how quickly the striker will take enemies off the board. Once you realize that, you realize that strikers are actually much better self and party defenders.
Understanding this is why the 5th edition fighter works so well, they made him a striker. One of the biggest wtf moments when I first opened up the 4e PHB was going to the fighter page and seeing it have a role of "defender". I was like, no thanks. I play a fighter, I don't want to be given a role of "defending others", I want to go out and kill stuff and be able to take hits while doing that. A ranger actually fills that role in 4e. And by killing stuff faster, is more effective at reducing incoming damage to himself and the party as well. Being 1-2 points of AC behind and 1 HP do not account for taking half the rounds to kill foes, especially tough ones. I would always run up to the biggest, baddest enemy I could find, and do up to 6 attacks against it. (2 twin strikes with an action point, and one or two off hand strikes). Dead. Always. Then my allies mop up. By sufficiently weakening enemies in 1 round of combat, an ally could even finish them off. Which, again, comes down to damage, not status effects. If you are picking a power, and power one does more damage, it's probably the best thing to take. If you want to win, why aren't you picking the best powers? Are you playing combat as a sport and want to toy with your enemies, sliding them around? Why? Unless you're CE that seems cruel. Just kill them and be done with it and move on to the next one.
As a striker, I would often estimate which enemies were peachy so I could swoop in and finish them off. Of course you can't move in between twin strikes, but you could use an off hand strike against a second target if you killed one off.