What are some songs that lack the electric that still kick some ass? Here are some that come to my mind.
The Downtown-Days of the New
Last Stop-Dave Matthews Band
Halloween-Dave Matthews Band
Keep on Rocking in the Free World-Pearl Jam (Neil Young cover)

Trying to think of some more. What are your picks?

Morphine kicked out the jams

First thing that came to my mind was the unplugged version of LL Cool J's Mama Said Knock You Out

Live version of "Psycho Killer" from "Stop Making Sense" soundtrack.

How about songs that still kick without ANY GUITAR at all?

LCD Soundsystem - Daft Punk is Playing At My House.
BFF - Song for the Dumped

"Country Honk"

ETA: I can't believe I saw the words 'Dave Matthews Band' and 'kick some ass' in the same paragraph.

This could be a long thread.

Pete Townshend's solo acoustic renditions of Drowned and Won't Get Fooled Again.

How about 'Pete Townshend's solo renditions of anything'?

I knew someone would say that so I uploaded a live version of Halloween that is freely available to fans. Check out at 2.25 and later:

http://s49.yousendit.com/d.aspx?id=1...B2COTJSATFNHD1

Anything from the early days that had Stephen Stills bringing the incredible sounds he produced with his Martin.

"Street Fighting Man" - Rolling Stones

Violent Femmes, first album.

Tenacious D - tribute

Neil Diamond - "Hell Yeah"

Ray Lamontagne - How Come or Danielle (You Got What I Want)

Well, it's a distorted acoustic guitar, so I think that it wouldn't count.

Regardless, it's a song featuring only acoustic guitar, and it kicks ass.

Days of the New - Touch Peel and Stand

I think the thing making the harmonics in the intro that also comes in halfway through the verse is an electric guitar. But it does kick with just the bass, drums, and cowbell

I'd throw down Dizzee Rascal - Fix Up Look Sharp, as well as countless hip hop and electro songs that have no electric guitar, but with drums, bass, and keyboards, could knock you to the ground

Ani DiFranco's first album.

The Other Side by Godsmack.

Les Claypool Fancy Band FTW

My 2 votes are from MTV Unplugged performances.

1. Stevie Ray Vaughan - Testify (simply amazing, on a 12-string on less)
2. Pearl Jam - Porch (at one point, Vedder picks up to guitar to smash but decides against it, that's how much it rocked)