semper ubi sub ubi (always where under where–bad grammar, but you get the idea)
populus qui habitabat sub latrinum (we are the people who dwell under the toilet)
scrofae es ex Hades (you are a breeding sow from hell)
Gallia est omnis divisa in partes tres (all of Gaul was diveded into three parts)
Or, “All Gaul is quartered into three halves.”
“Viridis esse non facilis est.” - Kermitus Ranidae
Or “Some people have enough gall to start a third party.”
Stercus fit. (Sh*t happens)
Catapultam habeo. Nisi pecuniam omnium mihi dabis, ad caput tuum saxum immane mittam. (I have a catapult. Give me all of your money or I will fling an enourmous rock at your head.)
Sentio aliquos togatos contra me conspirare. (I think some people in toga are plotting against me.)
“Carthago delenda est.” -Cato (Carthage must be destroyed.)
What’s the one that says “Don’t let the bastards get you down?”
Non Illemegati Carborundum
Confutatis maledictis flammis acribus addictis - “The damned and accursed are condemned to flames of hell”
This is only my favorite because in a certain Microsoft commercial, these are the words that are [sub](very appropriately)[/sub] sung as the words “Where do you want to go today?” are shown on the screen 
Okay, all you latin smartypants. What does this phrase mean (or is it just nonsense as is claimed)?
kiitoksia paljon
[sup]1[/sup]Motto for ASCAR
Gaudeamus igitur. (Let us then be joyful.)
Festina lente. (Make haste slowly.)
Nolite dolorem quia ipsum dolor sit amet. (Nobody seeks pain just because it is pain. Yes, this is the source of “Lorem ipsum dolor.”)
Uva uvam vivendo varia fit
That was the inscription on the sign in Lonesome Dove The characters in the movie didn’t know what it meant, “it’s a motto, it says itself,” but someone on another board said it loosely translates as “a grape only ripens in the presence of another grape,” which is quite appropriate to the main characters.
“In vino, veritas” - “In wine, the truth”
crap, I used to know many more.
WAG drawn from my handy dictionary would suggest that these are corrupted/oddly conjugated forms of
nolo–v. be unwilling; refuse
soleo–v. be accustomed; be apt to
summus–a. most extreme; highest, greatest, etc.
“Refuse to become accustomed to the heights”?
Bah, I’m sure one of these other folks can do better.
My favorites would surely include:
Nemo enim fere saltat sobrius, nisi forte insanit.-
No one dances sober, unless he is completly insane.
Aliquando et insanire iucundum est.-
It is sometimes pleasant even to act like a madman.
Malum consilium quod mutari non potest.-
It is a bad plan that cannot be changed
I like, from “Life of Brian,” this one: “Romanes Eunt Domus.” (“People called Romanes they go the house.” – Brian’s hideous attempt at “Romans go home!”)
What? Over 30 responses, and the greatest one isn’t there yet??
Let me share with you the Ultimate Wisdom of All Time:
"Varium et mutabile semper femina"
Meaning, of course, “woman is ever a fickle and changeable thing”. How utterly true.
It’s not a phrase, but is my favourite word…
advesperascere - to grow dark.
Whisper it. It sounds like shadows.
Ecce! In pictura est puella Romana!
Fran
Euty - shouldn’t that be Non Illegitamus Carborundum?
Personally mine’s “Fac me cocleario vomere”
[Moon Zappa]
Gag me with a spoon!
[/Moon Zappa]
For many more: http://www.bbc.co.uk/h2g2/guide/A218882
Veni, Vidi, Visa
I came, I saw, I did a little shopping…
mutatis mutandis - the necessary changes being made…
quid pro quo - I am a Republican and using Latin phrases makes me appear marginally intelligent when I am in pursuit of crucifying an out-going president.
I once posted this
VOMITORIUM MUTATUM
qui vomuit multos locus est quo nunc homo multum.
DUO VOMITORIA
hic locus admittit vomituros, ille vomendos
but no-one spotted the mis-use of the Gerund (I always get it confused with the genitive)
There are too many magnificent Latin phrases for me to name. I’ll just pick the first few that pop into my head.
Philip the Chancellor, fl. 1220, Bulla fulminante
The truth is crushed, stretched, and sold, while Justice sells her body on the street.
Vergil, Aen. 1, 461-3.
These are the wages of virtue! These are the tears of the world, the sorrows that touch all men. So have no fear.
Seneca, Apocolocyntosis Divii Claudii.
A cock is the master of his own dunghill.
Lord, do not judge me by my deeds,
For I have done nothing worthy in your sight.
Many, many more…but these are the only ones my memory is coughing up right now.
MR