Speculation -
A) Sony/Nintendo. Apple wants a piece of the video game market . . . badly. Their ability to tap into this market with iPod/iPad games has been a major source, and will continue to be a major source of revenue from AppStore sales. Apple has realize that there is still lots of money in this market, but sadly not with a keyboard and mouse, but rather with a controller. Apple has no plans, and there are currently no rumors in the rumor mill about Apple building a console, and their closest competitor is the Apple TV, which doesn't compete with the 360 or PS3. The market is already over saturated, and Sony, with a market cap of around $40 Billion, is an acquisition Apple could make tomorrow, and pay for the whole thing in cash. Sony has been poorly managed for a decade now.
B) Comcast. With over 27 million subscribers this would be a great means of establishing a contract based semi-consistent revue stream from the market. This would also be a great way of getting iTV sales from 250,000 - 500,000 annually to tens of millions. With a market cap, being similar to that of Sony, again Apple could pay for this out of pocket.
Personally, I would imagine a Sony acquisition. The company has great IP, and a fantastic brand name behind it. If Apple doesn't pick them up, expect Google to. I expect an acquisition Q3 of 2011.