Here are some boy bands who have never reunited. I haven't included some of the newer ones as they haven't been split up for long enough for a reunion to be on the cards yet:
Big Fun
Back in 1988 after producing Brother Beyonds only 2 top 10 hits, Stock Aitken and Waterman came up with their own boy band, Big Fun. Their first hit was a cover of "Blame It On The Boogie" in 1989. I remember my young self reading the lyrics to this in Smash Hits magazine and reading in the footnotes that it was written by Michael Jackson, unaware he originally sang it too. It reached a respectable number 4, but despite this very few people I speak to remember it.
They followed it up with another top 10 the same year with "Can't Shake The Feeling". However third single "Handful Of Promises" failed to make the top 20 in 1990. They teamed up with Sonia for their fourth and final top 40 hit with "You've Got A Friend" (no not that one) which did slightly better reaching number 14, but that was it for their chart career less than a year after it started.
When they finished they found themselves with a large bill to pay to Stock Aitken and Waterman making a reunion seem highly unlikely as they money they make will go straight to their former employers.
Yell!
Signed by Simon Cowell long before anyone knew who he was, Yell! had just one top 40 hit in 1990 with a cover of "Instant Replay". Their career came to an abrupt end shortly after when it was discovered that member Daniel James was really called Colin Heywood and was 32 instead of 23 which he claimed to be. By my calculation that would now make him 58, so would guess that if the reunion hasn't happened by now it probably never will.
Bad Boys Inc
The success of Take That in the early 90s was not instant. Their were given one last chance to score a big hit, and followed the advice of Ian Levine to cover "It Only Takes A Minute" in 1992. Ian Levine would then produce their following three hits and Take That had become a household name by the end of the year.
In 1993 Ian Levine decided to form a boy band of his own, Bad Boys Inc. If Take That and East 17 were the Coca Cola and Pepsi of the boy band world in the early 90s (you decide which is which), then Bad Boys Inc were very much the Virgin Cola. Their debut hit "Don't Talk About Love" only just made the top 20 and their following two singles didn't make it that far.
In 1994 they finally scored a top ten with "More To This World". This would be as good as it would get, two singles later their time was up. They did become the first band to appear on the National Lottery but this would be the last meaningful contribution they would make to the music world.
EYC
At the end of 1993 I was watching the Smash Hits Poll Winners Party. With the music being as mainstream as you could get and being quite clued up about all things music, I was surprised to come across a band there I'd never heard of before, EYC.
I've since found out that they were there in place of New Kids On The Block whose comeback single "Dirty Dawg" was deemed inappropriate for the awards. They were also an American group, but were virtually unknown in their homeland.
They were a lot more in your face than your average boy band at the time, but that didn't seem to bring them a great deal of success. They released five hits in the space of a year which brought them no top tens. The best they did was reach number 13 with "Black Book" which was more mellow than their other hits. They made a last ditch attempt late on in 1995 with "Ooh-Ah-Aa (I Feel It)" which bombed at number 33 and that was that.
As I recall they had just one fan from my school. Still that's one more than Bad Boys Inc.
Gemini
By 1995, Bad Boys Inc were finished, but Ian Levine seemingly was not. Enter Gemini, called that because they were twins. Their first hit "Even Though You Broke My Heart" only reached number 40. Then came their most successful hit, "Steal Your Love Away" which reached number 37. Final hit "Could It Be Forever" reached 38, but they never attempted to complete the sequence by getting to 39 with a follow up. Of course when people think of Gemini these days they think of their namesakes (spelt Jemini) scoring nul points at Eurovision. Compared to what they could have been remembered for, it may not be such a bad thing.
Upside Down
Upside down were formed on a BBC documentary called "Making Of The Boyband" which I've posted above. After selecting four members from photographs followed by some karaoke, the management started to look for some actual music for them to sing.
After much exploring they decided to bring in none other than Ian Levine. Their first hit "Change Your Mind" was a blatant rip off of "Careless Whisper". By the end of the documentary it had reached 35, but possibly helped by the documentary it ended up reaching 11. Follow up "Everytime I Fall In Love" only managed 18 and then came "Never Found A Love Like This Before" which was clearly a rip off of Take That's "Pray" with an almost identical video. It reached number 19. Their final hit was an actually cover of "If You Leave Me Now", but this would only reach 27.
Following this, their record label World Records went bankrupt and that was the end of the band. They did comeback as a rock band called Orange Orange but with no success.
The documentary above was said to be the inspiration for Channel 4 comedy "Boyz Unlimited" a few years later.
The One
Very little can be found on boy band The One. They had their own mini series on GMTV before releasing their only top 40 hit "One More Chance". Member Billy Worth would reappear in the Channel 4 comedy "Boyz Unlimited" a few years later. According to his IMDb profile he passed away in 2008, but he was also working as a publican in Melbourne in 2010. Make of that what you can.
North and South
Another boy band with their own TV series, North and South had a show called "No Sweat" on CBBC. In 1997, after that infamous interview with Brian Harvey which brought East 17 to an abrupt end, their manager Tom Watkins put this band together via adverts on teletext.
Their debut "I'm A Man Not A Boy" reached number 7, but their three follow ups, included the theme tune to the show, didn't do so well. Once the TV series ended, so did the band.
Northern Line
Several years ago I was working at a place where many of my colleagues were fans of Big Brother and would discuss the show on a daily basis. Not watching the show myself, I could not contribute to these conversations until one day somebody said "apparently Ziggy used to be in a boy band called Northern Line, does anyone remember them?" to which I said "I do". I was the only one.
Although not the first group to name themselves after a line on the tube (Central Line anyone?), you can almost sense how awful they would be based on the name alone. They didn't disappoint, with their debut "Run For Your Life". It didn't end there, they followed up with hilariously awful "Love On The Northern Line". One further hit followed and that was that.
Member Dan Corsi did actually appear on the Big Reunion when he auditioned to become a member of 5ive. However, he refused to sing at his audition and unsurprisingly didn't get the part.