I have an ego. No, it's true, I have one - and there are days when it's big enough that Malygos's chamber couldn't hold it. On other days it's smaller than that urn you use to summon Nightbane. Fortunately, it generally floats somewhere between the two, in a healthy medium of confidence and fear.
Most of this ego comes from my days of tanking, when I was fortunate enough to have some amazing healers at my back, and learning more than one lesson the hard way. Because of this though, I have a healthy respect for the healer/tank relationship - and I understand where the DPS fits in this psycho family as well.
It came as a great shock to me, though I should have known better, that many players (especially DPS) don't run with tank/healer frames - much less all raid frames. I personally don't understand it, though I suppose it lets them DPS in ignorance. They wander aimlessly around the encounter, out of range for heals, and then wonder why they've died.
There's also the DPS that even after what, five months in Naxx, still haven't figured out that the Death Knights in the military wing have giant cleaves? I had the (dis)pleasure of running with an arms warrior in my last Naxx (Damn you TT for not dropping again) who quickly moved down my priority list for heals.
Where you rank
Let's be honest, we're not all equals, especially in raids. My job is to heal the tank - anything else is a pure bonus. My healing order is generally MT>OT>Me>Other healers>DPS>Pets>Dumb DPS. That's right, I'll heal that pet named "Cat" before I'll heal your cleave eating self - providing the hunter isn't part of the Dumb DPS group.
There are several ways to move yourself up/down the list however (Jong at Forebearance has a post touching this as well), and I'll give you the quick run down of the Minus and Plus tips.
1) (Minus) Don't call for healing. Ever. Doubly so for hybrids who have heals available to them. Especially if you're a tank. Calling out "Joetank needs heals" is pretty dumb. You're the tank - of course you need heals. By the time your brain has registered that you have low HP, you say it on vent, it gets to me, I register it, then cast...you're either dead or you've just irritated your whole healing team. ***Exception - if you're picking up adds and will be taking a world of damage, call out you're picking up adds - that's what we need, and that's because we're not going to get a break.
2) (Minus) Don't call for cleansing. Again, our raid frames show it. You're either out of range, or have been triaged down for healing or someone who follows the plus rules.
3) (Double Minus) Don't get lippy about heals after you've died to something dumb. Whoever that Arms warrior was who kept lipping off "WTB Heals" after dying to cleaves - guess how many more heals that guy got from any of us? (As poetic justice - he died in the very first Shadow Fissure on KT).
4) (Minus) Don't post the DPS meters in raid/party. We didn't get to participate in them, and you're just stroking yourself. Maybe next time we'll take pity on the guy in 3rd and just let you spend some extra time looking at the floor.
5) (Plus) Thank your healers, and compliment them on a job well done. Clutch heal saved you a repair bill? Smooth run overall? Give your healer a quick pat on the back and he'll remember you next time.
6) (Plus) Don't. Stand. In. Fire. Can't say it enough, yet to this day, you see people standing in fire/poison/ice/shadow. When was the last time standing in a pool of inky death was a good thing? Other than Hodir, when is hugging someone shooting lightning out of their eyes beneficial? Yeah - quit standing in the poison in AN too you idiot. I'll let you die just so the bear can t-bag you.
7) (Plus) Watch the CC breaking. If you're not the tank, and you're breaking CC, I'm going to let that punch to your face bleed a while before I heal you up.
8) (Plus) Know the healing classes. Here's a tip, from MT to Raid healing, your best options are....Paladin, Disc, Tree, Shaman, Holy. Don't put your Holy priest on the MT and your Paladin on the raid. Sure, they can do it - but if they aren't smart enough to switch on their own, they'll silently hate you forever.
9) (Plus) Help us help you. Use the lightwell. Use your healthstones. Burn a GCD to toss an instant heal on yourself. Stay. In. Range. We understand it might lower your personal DPS, but we have limited GCDs too you know.
10) (Plus) Be helpful. Don't bitch when you're asked to cleanse, bubble/HoS, BR, or whatever. Do it and get back in the rotation. We'll remember it later.
Bottom line is don't be the stereotypical dumb DPS that we all curse about in PUGs. Remember that your healers are generally doing their best, and only occasionally 'let' you die.