Maybe not rocking, per se. But at least making good to great music.
Yo La Tengo comes to mind.
As does Tom Zé and Bob Dylan.

All released excellent albums just last year.

Damn.

Oh, I thought you were predicting about 20 years from now. Um... Tom Waits?

God, there's quite a few. But I'll just mention Half Man Half Biscuit and The Church.

Motley Crue

"....years gone by, we're still kickin ass....." - Kickstart My Heart

The Fleshtones
The Wedding Present
The Chills

Yo La Tengo not rocking?

Have you seen them live in recent years? Georgia is still rock steady and Ira's freak outs are as extreme, loud, and rocking as they have ever been.

And of course Neil hasn't lost a step.

Solomon Burke

I'm not saying they don't rock. I'm just saying that your picks don't necessarily HAVE to rock. I know YLT brings the rock. Like a freaking quarry.

Sonic Youth; it seems weird that they're over 20 years together now...

Willie Nile

NOFX

and they are still terrible live. holy cow... you'd think they'd been to the sunnO))) school of drone after the last time i saw them in july.

Notoriously inconsistent.
I've seen them twice. First time was amazing. Second time was crap.
Give 'em another chance.

I think poster children is still together and they started in 87
geezus

Totally disagree. I've seen them 10-12 times over the years, and while they are often different, they are always interesting.

Mudhoney are close.

The first YLT show I saw - in '00 at Champaign's High Dive - is my #1 of all time. The second - '03 (?) at The Vic - is certainly up there, too.

Excellent the one time I've seen them in I think '97, Bottom of the Hill, SF.

KISS

i knew who the thread starter would be without looking

I liked Yo La Tengo when I saw 'em live way back when..then grabbed a CD a few years later when I saw one and remembered really digging the show...totally different band...I've never really warmed to their recorded sound.

Didn't know Poster Children were a national act...saw 'em open for somebody when they were just being billed as some band from someplace in Central Illinois. I remember liking them too...so I'm glad if they went on to have some success.

Oh...and I'll add Willie Nelson to the list, he put out one of his stronger albums just last year. And, Prince's album was pretty good as well.

Is Lou Donaldson still making record? He's still playing live and still sounds great.

Hamiet Bluiett, a local baritone sax player from Brooklyn, IL, who I believe has national attention, worldwide from his touring schedule, is still going strong as far as touring, but again, not sure what he's recorded lately if anything.

Kraftwerk just put out an amazing live disc in like 2005 or 2006...does that count?

Subhumans, the Canadians not the English ones just put out a strong record after years off duty for some jail time, but they do go back over 20 years. Actually, heard a few old hardcore bands put out strong albums the last few years, including a pair of good ones from TSOL.

Has Green Day been around 20 years? American Idiot was my favorite thing they ever have put out.

Tons more for sure, but there's a few off the top of my head in a long rambling post...

for me i think about '98 or '99, warehouse, lacrosse wisconsin
and then i saw the poster
on a "Clarissa Explains it All''s wall on TV-about the same year.
(Or was Blossom?
Either way I was 17 and ready to fuck the shit out of bof'fem girls)

holly shit, Green Day HAVE been around 20 years.
how the fuck did that happen.

i dont know i just checked out that wikipedia entry also
it was two kids at 14 in 86 then they didnt take the name green day or release anything until 89...

but still
18 years?

they haven't put out anything in a little while, but Gang Starr are coming close to 20 years.