Allons-y

Allons-y, according to the Tenth Doctor, was French for "Let's go". (TV: Midnight)

The Doctor
It was one of the Tenth Doctor's favourite sayings; he especially wanted to say, "Allons-y, Alonso", (TV: Army of Ghosts) which he eventually said to Alonso Frame. (TV: Voyage of the Damned) The Twelfth Doctor once claimed that he was able to say it due to his precise control over the TARDIS translation circuits. (COMIC: Four Doctors)

The Doctor used the exclamation while drinking with Xylem Maple Dorm. (AUDIO: Death in the New Forest)

It saved his life on Midnight by proving that the being possessing Sky Silvestry had stolen his words. (TV: Midnight)

Both the Doctor and Jackson Lake, a human who believed himself to be the Doctor, used the exclamation simultaneously while facing a Cybershade with their respective screwdrivers. (TV: The Next Doctor)

When the Doctor used the exclamation in the company of Lady Christina de Souza, she responded by speaking in French, leading the Doctor to observe that they were "made for each other". (TV: Planet of the Dead)

The Doctor used the exclamation as he was taken to Area 51 by the US Army. (TV: Dreamland)

The Tenth Doctor exclaimed the phrase as he, along with twelve other incarnations, combined the power of their TARDISes to use a stasis cube to freeze Gallifrey in a pocket universe. This, combined with the Eleventh Doctor's "geronimo!", came to the irritation of the War Doctor. (TV: The Day of the Doctor)

The Doctor described it to Addams as a word of consolation to the soul in times of need. (TV: The End of Time) He was last heard using it during his final reward, as he proceeded to flee from the Gentlemen of the Dice with George Litefoot. (AUDIO: The Jago & Litefoot Revival)

Mr Clever once used it when mimicking the Tenth Doctor through the Eleventh Doctor's body. (TV: Nightmare in Silver)

The Thirteenth Doctor uttered the phrase when working with the Corsair and Team TARDIS to open a door with one hundred handholds. (COMIC: Old Friends)

Others
In April 2004, Neil Redmond used the phrase. (AUDIO: Uncanny Valley)

While piloting the Doctor's TARDIS with her "companion" Natalie Morrison, Donna Noble exclaimed "Allons-y!" as they departed. (AUDIO: Spinvasion)