Dizzys has gone by a few names over the years, but in its current incarnation it styles itself as a slightly threadbare upstairs lounge, with pool and Wii down below. Alongside the regular mojito, they also have the obligatory house specials.
Dizzys
28 King William Street,
EC4R 9AT
www.dizzysbar.com
First off, stay the hell away from the pinkari mojito. It tastes like liquid hate, and is toe-curlingly sour. It should, in my opinion, be classified as a war crime.
The straight-up mojito is a bog standard Bacardi affair. It's pretty pedestrian; watery and a little too sweet.
I won't keep going. If you're after a decent mojito, there are many better venues in and around EC4.