So much misinformation in this thread.
Right now ranged DPS are second to many melee dps specs. Of the melee specs, these are the top (in this specific order):
1. Feral - Ferocious Bite hits incredibly hard, especially with early access to Savage Roar and Tiger's Fury. Other feral attacks are powerful too, especially pounce in the opener. I've been crit for 2.2k-3.2k by Ferocious bite @ 29.
2. Windwalker Monk - Fists of Fury is where most of the monks damage is centered now. This gives them a pretty decent burst button every 30 seconds, even though their other offensive abilities are still strong (Tiger Palm, Blackout Kick). They also have Karma, Expel Harm, Fortifying Brew, and Healing Surge as strong defensive abilities, combined with Roll, Disable, Flying Serpent Kick, and Tiger's Lust as strong mobility abilities.
All around, Monks represent the most viable Melee DPS outside of just bursting someone as feral.
3. Arms Warrior - Arms is strong, though their main damage comes from Whirlwind (AoE) and Rend (dot). Execute is strong when they are in range, though they don't get Sudden Death yet, and Slam is now a talent in a tier 29 warriors don't have access to yet. So Warrior is basically just Charge > Rend > MS > Whirlwind, as much as possible, and they can Pummel which makes them a difficult class to counter when they sit a healer. They can put out a lot of constant pressure, but I still think Feral/WW are better.
4. Enhancement - As one of my favorite specs to play, I wish I could rank them higher than
#4 , but alas, they are middle of the road compared to the previous 3 melee specs. They have great offensive pressure between burst attacks every 8-10 seconds, Slows, Purges, and Wind Shears, as well as great defensive moves with Healing Surge, Stone Bulwark Totem, and Ghost Wolf form. In fact, because of their other abilities, they can potentially beat out the other more powerful melee specs. I've countered Feral druids because enhance can interrupt their long heal casts and purge their Rejuve, while still doing full damage.
5. Ret Paladin - Ret isn't as strong as an Arms Warrior, but has much better defensive moves, including heals that can rival an actual healer. While they don't necessarily have the offensive pressure a Warrior does, they are still a threat, capable of unexpected burst from random crits. Divine Shield, Lay on Hands, Cleanse, and Divine Protection make them a great counter to a variety of other classes.
Honorable Mention - Rogue, Fury Warrior, and BM monks all get honorable mention, because they do subpar damage, are one trick ponies, or just don't have what it takes to make it in the top 5 melee DPS specs.
Okay, so I bet you're wondering why I listed the top melee DPS specs in the game rather than the top ranged, as the OP had asked for. Quite simply put, even the bottom ranked melee are viable threats against the best casters. Boomkins lost their instant burst from Starsurge procs. Elemental Shamans lost their ability to cast Lighting Bolt while moving, and Spriests lost their CC and insane burst. So if I had to rank the ranged DPS, they would be listed after the top 5 melee, but above the honorable mentions, probably in this order:
1. Spriest - This spec is all around the best caster DPS for a variety of reasons. They still have strong burst between Mind Blast, Devouring Plague, and Dots. However, this burst is nowhere near as strong as it was. Even the most glassy of Spriests are going to burst crit for less than 2/3 of a players health. Devouring Plague is a great healing move though, which helps keep them alive during burst openings. Their other offensive moves are also very strong, between SW

ain, Vampiric Touch, and Mind Flay. All help Elemental Force proc quite frequently, making it difficult to justify not dispelling them from your teammates, even though doing so will result in being feared by Vampiric Touch dispels.
Spriest are just the most capable in terms of offensive pressure, despite the fact they don't have any form of interrupt or CC, even though they do have strong heals and bubbles on top of their good damage. They are just capable of mitigating so much pressure themselves without really losing any, which is why I ranked them
#1 ranged.
2. Mage/Warlock - I'm ranking these two at the same spot because they are quite literally identical in the roles they fill in pvp right now. Both are strong classes damage-wise, with the only abilities to completely take someone out of the game right now at level 29. Despite the 7 second duration on Fear/Poly, they are still chain-able, neither one DRing each other, and can potentially serve to completely nullify another player. While their burst isn't nearly as strong or constant as other DPS specs, they do have the unique ability to create an opening for burst that can kill someone, even if they must coordinate it do do so.
Mages get Counterspell in addition to Polymorph, while Locks get automatic dispels from their Imp pet. Both are valuable utility.
3. Boomkin/Elemental - Again, I listed these two specs together as they seem to have about the same level of viability and just different versions of the same toolkit. Both are capable of burst comparable to Spriests, but require the ramp up time and have to stand still while they turret their damage into enemies, while juking kicks and casting off heals. While they bring notable burst, neither one brings much pressure outside of their burst windows, due to the fact their dots aren't really all that strong. Boomkin had Sunfire/Moonfire bound to the eclipse mechanic in a way that makes it rare to have both on any number of targets at the same time, while Elemental shaman never had much in the way of strong dots between Flame Shock and Searing Totem.
While they both still have crazy amounts of other utility outside of damage, they still don't compare to Mage/Warlock in terms of CC because their abilities have long CDs (Roots + Solar Beam, Thunderstorm), though the do provide unique (albeit situational) utility not available to any other class at this level. At this point, both are completely under represented specs, as I have encountered very few Boomkin or Elementals since 6.0. I have encountered MORE warlocks and mages, to be perfectly honest, and they've seemed like more capable classes given their toolkits by comparison.
4. Hunters - Taking up the last spot, hunters are definitely not as competitive as they were in past expansions, with the removal of pet CC, scatter shot, and the significant reduction in burst. They can still line up Freezing Traps and Conc shot people, but outside of their 30 second cool down, they are just an average derps class.
Additional thoughts: Melee really take center stage right now vs ranged DPS, coming with the pressure needed in fights without having to ramp up damage through easily interrupted spell casts. This doesn't mean that ranged are terrible, they just don't represent the gold standard in DPS they did for MoP. Classes like Mage and Warlock have a higher skill cap than they did before, requiring that a player be really dedicated to their class to get the most out of it.
All said, everything feels a lot more balanced this patch compared to the last two expansions, and all DPS are relatively in line with each other (with obvious exceptions of course).