From Somewhere In Pants:

I'm all out of pants

Crazy Pants

Puppy Pants

Don't Give Up On Pants

I'm Not In Pants

Could It Be I'm Falling In Pants

and Without Pants

to name but a few...

Then there was his sister's hit, Paper Pants ;)

Mark Owen had a minor hit with his Four Minute Pants...

the Pantszone hits:
Love Me For Pants
A Picture of Pants
Father and Pants (pinched from Cat Pants)
And my personal favourite...
The Key to My Pants
I've just realised how sad I am...

Would also like to point out that Love Me For Pants was originally a hit for the Osmonds. Another pinched cover version (though not from the Osmonds) was of course So Take A Look At Me Pants, by Westpants and Mariah "My Girdle's Too Tight" Carey. Then there was 5ive's original hit, When The Pants Go Out.