old kegged beer?

What is the longest you have had beer on tap and it still tastes good? I've had two tapped that i haven't drank from for six months and i'm a little affraid that it will have it's revenge on me because of neglect (if the sugars haven't permanently glued the taps shut)

Prior to these two, i've never had a keg last more than a month. I feel a little bad ignoring them. One is an octoberfest and the other is a plain ol' pale ale.

depends on the beer you brewed. if its a belgian wit, 6 months is past its prime, even in the bottle.
if it was a porter that was oaked, it might just be coming into its prime.

I say, taste your two beers. If they are good, then they're good! You'll be able to taste if they're getting funky or stale.

If you kept em under CO2 pressure and they were relatively chilled...you're fine.

I'd clean the lines before tapping one.

Like Mal sez it depends on the style. I have a barley wine I brew last May that has just started to taste decent in the last couple of months or so and seems to taste better with each passing month. I almost poured it out on several occasions. Now I'm glad I didn't.

Thanks guys, one was ok, the other was pretty nasty