Apparently the Purple Mangosteen (Garcinia mangostana) is referred to by some as the Queen of Fruits.
"Mangosteen is sometimes known as "The Queen of fruits" in parts of southeast Asia, notably Singapore and Malaysia. It is believed to have "cooling" properties that counteract the "heat" of durians, the so-called "King of fruits"" says wikipedia .
Also, Hula Brothers, a company which sells the trees, says
"Mangosteen is a slow growing understory tree native to Malaysia. The fruit is highly prized and considered the "Queen of Fruits." The round, purple, smooth, thick-skinned fruits are the size of a small apple and perhaps the most delicious fruit in the world. "

http://www.hulabrothers.com/store/cart.cgi?action=link&product=4

On the other hand, in the Middle East the Pomegranite Punica granatum is called the Queen of Fruit. Oman Today also notes "The fruit was also the personal badge of Queen Isabella of Aragon and the Roman Emperor Maximilian, and has a long history as a national symbol in Spain. "

http://www.apexstuff.com/ot/200703/natural.asp
http://en.wikipedia.org/wiki/Pomegranate

In parts of America, however, it is the Peach that is known as the Queen of Fruit. The Illinois Times says:
"Peaches, known as the queen of fruit, rank second in popularity to the apple. A medium-sized peach is a healthy treat boasting just 45 calories, most from natural sugars. They are also a good source of fiber and beta-carotene, have only a negligible amount of fat (less than a tenth of a gram), and no sodium or cholesterol"

http://www.illinoistimes.com/Springfield/article-3326-fuzzy-queen-of-fruit.html

In India, the mango (no relation to mangosteen) is called the Queen of Fruit. "Called The Queen of Fruit, the mango features prominently in the symbolism of India and Tibet. It is an offering suitable for the gods. " says Khandro.net

http://www.khandro.net/nature_plants.htm

The Pineapple is also called the Queen of Fruit.
www.actahort.org/members/showpdf?booknrarnr=682_302

Also, the Pear: "Pears are fruit of the genus Pyrus, more temperamental to grow than the apple and less common, but called by some "the queen of fruit"" from "On food and cooking: the science and lore of the kitchen By Harold McGee"

Another Queen of Fruit is the Litchi "Taiwanese people call litchis the queen of fruit. They grow between April and August, depending on the variety."
http://www.taiwanembassy.org/US/NYC/ct.asp?xItem=29896&ctNode=3483&mp=62&nowPage=6&pagesize=30

On the other hand, "America's queen of fruit" is the watermelon!
"While the ‘superfoods’ A-list changes from day to day, the watermelon may have more claim than most to be hailed as a food celebrity. It’s sweet and juicy, low in calories, quick and easy to prepare, and packed with essential nutrients. “Nutritionally, watermelons are fat free, whilst giving you a healthy dose of vitamins A and C, as well as fibre,” says dietitian Azmina Govindji." in the PPP Healthcare site. http://nutritionandfitness.axappphealthcare.co.uk/eating_features15.html

I'm about out of energy for looking up queens, but here is one more:
"people call strawberry "The Queen of fruit", because it is rich in so many good health – nutrients"
http://www.thestrawberrydesserts.info/strawberry-desserts/strawberries-%E2%80%93-the-overlooked-perennial.html

I'm going to pick the strawberry, so to speak, for my Queen. Mainly because the strawberry is the local ruler where I live.
www.lastrawberryfestival.com
And, it's featured in a local brew from Abita:
"Abita Beer Strawberry Harvest is made with the sweet juice of Louisiana strawberries grown in Tangipahoa Parish" says
http://blog.nola.com/brettanderson/2009/04/its_strawberry_season_in_louis.html
http://blog.nola.com/brettanderson/2009/04/medium_Abita-Beer-Strawberry-Harvest.jpg

And, here the Strawberry is not only the Queen of Fruit, but it has its own human Queen every year:

http://www.laffnet.org/Ponchatoula_Strawberry_Festival/theresa%20Pevey.jpg

The queen of all fruits is "Mangosteen" and the King of all fruits is the "Durian."

---quote---
In 1903, explorer David Fairchild referred to Mangosteen as, “the queen of fruit,” and so coined the term that still exists to this day. His reason for doing so was because he thought very highly of it and so wanted to imply that the fruit was regal by nature. It is also important to note that he was, all things considered, an entrepreneur and wanted to capitalize on his Mangosteen enterprise. As far as any one is concerned, the connection between Queen Victoria and Fairchild’s quote is that there isn’t any and so is apparently, according to Mangosteen.com, “internet fiction.”
---end of quote----

mangostin known as the queen of all fruits