If my character were level 100, I would...

[GrumpyOldMan]

Find a new Referee

 

[Wulf Ratbane]

Find a new Referee

We have a winner!

 

[Tetsubo]

World Domination.

I've always thought I'd run the place better...

 

[Treebore]

Be bored silly.

 

[Darkness]

Depends on the setting.

In the FR, I might apply for a job as Elminster's gardener or something.

In Eberron, I'd assume that's 100 in the binary system (in other words, level 4).

 

[DaveMage]

Yes what would you do if you had a 100th level character?

Try to fight each of the Nine Lords of Hell all at once - just for kicks!

 

[Zappo]

Two words: ALE and WHORES!!

 

[Krug]

... realise I still had to wash my own cups and make my own bed.

 

[Shade]

Enjoy the sheer magnitude of the power at such levels, the almost crazy amounts of abilities and items, and take part in multiverse-ratttling events on a daily basis.

But most of all, I'd thank my DM for putting it all together!

 

[gamecat]

were it Greyhawk: Make a rogue/bard/swashbuckler with a redhead fetish - try and chip some ice off of wee jas's heart.