When you’re pitching your story to publishers, please don’t waste paragraphs describing each character’s powers. That’s space you could be using to develop personalities, character traits, the plot, relationships, etc. As a rule of thumb, I would recommend keeping it simple–generally, if you need more than 20 words to describe a character’s powers, there’s probably too much going on. (Main exception: if that extra space is crucial to understanding the plot).*
Here are some of the popular characters that have been introduced in the last ~30 years.
Wolverine has claws, regeneration and agility.
Cyclops has an eye-beam.
Spider-Man has agility, spider-webbing and danger-sense.
Storm can fly and control the weather.
Deadpool has regeneration, agility and sometimes strength.
Hiro Nakamura can stop time, teleport and travel through time.
The Haitian can erase memories and nullify powers.
Pretty much every other character on Heroes has a single power.
Reed Richards is smart and stretchy.
The Invisible Woman has telekinesis and forcefields. And, umm, invisibility (though you hopefully knew that one).
Iron Man is tough, smart, and armed with lasers and conventional arms.
Hellboy, Hulk and Ben Grimm (among many others) are just super-tough.
The Human Torch, Iceman and Static Shock (among others) control an element, often alongside flight or another travel ability. (Well, ice and electricity aren’t elements, but they’re very similar as far as superhero writing is concerned).
Virtually every popular hero introduced in the last ~30 years has superpowers which could be summarized in ten words. (Can you think of any exceptions? Spawn, Sandman and possibly Invincible are the only ones that came to mind).
Almost all of the modern characters that have really caught on have only a few powers that are easy to explain. This is particularly true–perhaps almost necessarily true– when the story is about a group of superheroes rather than an individual. You probably don’t have enough space to develop three powers each for a group of five (unless perhaps they’re very generic and require extremely little explanation). When you’re dealing with a cast as large as X-Men or Heroes, I’d only recommend giving 3+ powers to characters that are unusually important.
*Off the top of my head, the only story I’ve read where the superpowers would have deserved more than two sentences in a page-long summary is Bitter Seeds. Its superpowers come from demonic negotiations with human-hating spirits, which significantly affects the mood (e.g. the protagonists kill innocents to pay off the spirits) and drives the plot (e.g. the two main protagonists part ways over how to handle the spirits). Don’t spend more space on the details of the superpowers unless those details really help us understand the plot and/or characters.