I use kitchen loosely, it would be a bar/kitchen. don't really need an extra guest room, but definitely a bathroom.

Agreed, the basement could be used as an entertainment / media room, or just extra square footage for potential buyers.

Most buyers like finished spaces. Would fix it up and enjoy and make money at resale.

@g8edcowgirl what is the square footage of the room? Do you have some photos?

You'd probably want to stick with a half bath if you're planning on a bar and kitchenette... Depending on the size and if you're thinking a theater room, you may want a full bath with a Jacuzzi tub.

It's a big basement. I will use some of it as storage area.

Go for it! The more living space to advertise for resale - the better. If you can get a minimum of 500-600 sf after bathrooms, bars etc... you will be in good shape. All that said, depending on your budget take a close look at what needs to be done with plumbing when you're working out the design. Digging up floors and adding fixtures can run cost up quick.

Remember, the appraised value of below grade footage is generally about half of the above grade footage. This is where the standard for your area really comes into play. If everyone has a finished basement and it's expected, then it may devalue your home not to have one. However, if it's seen as an overimprovement for the area, you may not get your money out of your investment. Speak to an appraiser in your area and see what they say about cost vs return.

That is a great point smartin1, however, there is nothing like updating your facebook status on a full wall projection screen :)