What's the Biggest Planet ever Discovered

HOW BIG IS IT??

IS IT BIGGER THAN JUPITER??

Difficult question to answer actualy. When we start to get into planets larger than jupiter we are entering the realm of stars. In fact there is no clear line between stars and gas giants. Unless we define a planet as a large body of gravitational bound gas that is not heavy enough to achieve fusion... but that would include brown dwarfs, and those share far more charactorists with the sun than the earth.
So in conslusion... depends what you mean by planet.

Article from Sunday, April 17, 2011
http://nanopatentsandinnovations.blogspo…

WASP-12b turns out to be one of the largest exoplanets found to date

The planet is more than 250,000 km across, with its atmosphere swollen by the intense heat it receives from the star, making it a so-called ‘hot Jupiter’.

the diameter of jupiter = 142 984 kilometers at the equator

You may be right, Gint depending on which measurement you take for 17b. If you take the low estimated size, then "no" but if you take the higher one, then "yes" but you get a TU from me for throwing it out there.

Actually Wasp 17 b is bigger than Wasp 12 b.

http://en.wikipedia.org/wiki/WASP-17b