Ecto-shields
Ghost Stinger
Spectral Manipulation - The ability to reshape his ghostly form around blasts or other attacks
Ghostly Wail - A mixture of spectral energy and sound waves, this attack is by far Danny's most powerful weapon. It is difficult for him to control and causes quite a lot of collateral damage. Once Danny uses it, he usually runs out of energy and reverts back to human form, though there have been signs in recent episodes that he is getting better at using it.
He first uses this power during 'The Ultimate Enemy', when he is forced to fight an evil future version of himself who has already gained the power. His gaining of the Ghostly Wail is what proves that the future he's seen can be changed, as his future self hadn't gotten that power until about ten years later.
Ice Powers - Danny develops ice powers, as shown in both the episode and video game of Urban Jungle. Why he has this power and how it works isn't really explained, or if it is, I missed it, but Danny was trained in its use by the new ghost Frost Bite. The ghost sense is said to be a part of the ice powers somehow. He mastered the power in what appears to be a pretty short time, and it is shown to be quite powerful. We don't know how the use of these ice powers affects him, but it could be a power that uses up much of his energy like the Ghostly Wail.
Frost Bite shows several uses, making a snowball, a large ice crystal, an ice statue of Danny, and an ice sword. The density of the ice and its shape is controllable, and possibly the temperature as well. The ice beams can be shot out of the hands or the eyes, and they might be shown in other ways later on.
One thing to note is the fact that Danny ends up shivering uncontrollably and can't manage to keep warm until he lets out all of the 'cold energy'. This could mean that he has to use these powers or he'll end up in that same state again, though this might be proven wrong in later episodes.
Fire Powers - In the video game Urban Jungle Danny eventually gains some fire powers. This may or may not end up happening in the actual show, though I, for one, hope it doesn't. If they do show up, it's likely that they'll work the same way the ice powers do and have the same toll on him.
Flight - The ability to hover in the air and to fly at high speeds. Danny is capable of flying at 112 miles per hour near the beginning of the series, and is likely faster now. Often while flying Danny's legs disappear and instead he has a spectral tail. The reason for this is unexplained, though it might have something to do with aerodynamics.
Ecto-blasts - Ectoplasmic energy focused in the hand and shot towards enemies in the form of a beam. Danny's most basic attack, it requires little energy. His beams take the form of green energy, and can be larger or smaller according to the purpose. 
Ecto-blasts - Ectoplasmic energy gathered into the hand and fired as a beam towards the opponent. Vlad's ecto-energy is a pink/purple colour, and can also be fired from the eyes, as seen in 'Maternal Instincts'.
Ecto-shields - Ectoplasmic energy used to deflect an attack, either physical or ectoplasmic. It can be formed into a compact rectangle of energy or a dome or circle, though Vlad seems more fond of creating rectangular shield. They are also pink/purple in colour.
