Mine has my rattery logo and name on it. It’s a logo I’m really fond of, and I think the mug looks great. Always makes me smile!
Are All the Fishermen Liars or Do All the Liars Fish
“That’s the beauty of it!” 
I have one I got from a work activity. It says Treasures of NOAA’s Ark and has a crate with the NOAA symbol coming out of it. You can see a picture of the logo here.
Using my alternate mug this morning.** Cafe Du Monde**
Favourite work one - black inside and out, with white scrollwork type pattern and the stylised B (for Buffy) logo. The black inside was handy as it never really got washed properly at work, just rinsed out between batches of black coffee and green tea. 
Favourite home one - a tacky native american style painted mug, souvenir of New Mexico. Nice bright colours, completely inauthentic I’m sure, but mainly used as it holds about half a pint of coffee, which is *very *important first thing in the morning. Even if it is instant coffee rather than “real”.
Mine has a panorama of Salzburg, Austria, a picture of Mozart, and his name on it.
Mine is a rather oversized ceramic mug that says:
Eggs 'n Things
Honolulu, Hawaii
www.eggsnthings.com
No, I did not steal it. Bought it on our last trip to Hawaii six years ago. It replaced my previous favorite that I dropped and smashed, another rather oversized ceramic mug bearing Van Gogh’s The Starry Night.
That is the one I use for pens/pencils at home! I also have the Far Side Suggestion Box mug.
I don’t drink coffee, but my mug at work is this. The other side says Stay Awake, Stay Employed.
My favorite doesn’t say anything on it, other than an Ozy and Millie logo. It’s also got a picture of Llewellyn then dragon reclining with a rose in his teeth.
Another favorite O&M mug (that I use for pens due to cracks) has Ozy sitting on a curb, with a sign next to him that says “Will provide pseudo-insightful commentary for food.”
A third favorite has a variety of Shakespearean insults on it. YOU RAMPALLIAN! YOU FUSTILLARIAN!
“Martinez Lake Resort And Marina”
.
My favorite mug is large and purple and on one side reads:
All Lives Should Have 9 Cats
the other side has:
It has a simplied line drawing of Jayne cobb holding Vera with the line “It’s Vera, It’s my favorite gun” 
Inserting and Replacing Text
a – Append text after the cursor
i – Insert text before the cursor
o or O – Open a new line below or above the current line
R – Replace text starting with the current character
ns – Substitute n characters
n<< or n>> – Shift n lines one shiftwidth to the left or to the right
:ab a b – Use a as an abbreviation for b
Deleting Text
ndd – Delete n lines beginning with the current line
nx – Delete n characters beginning with the current character
Etc., etc. It continues on in that vein in 4 more categories: “File Commands”, “Cursor Movement”, “Searching and Copying”, “Cool and Unusual”
The NSA seal.
I am unreasonably proud of that mug.
Most of my mugs have logos and slogans from the companies I 've worked for. I’ve gotten them for free over the years. I have so many that I never felt the need to buy any more.
“Mr. Osborne, may I be excused? My brain is full.”
“You may all go to hell and I will go to Texas” - Davy Crockett
I keep this one on my desk because all of my co-workers know I’m originally from Texas, and now I live and work in Kansas City.
My “Fucking Bears” mugs.