He was in the Big Brother house for all 93 days, but Glyn Wise eventually left the Channel 4 show in second place.
The 18-year-old from Blaenau Ffestiniog entered the house wearing a lifeguard outfit back in May and reached Friday's final of the seventh series.
Glyn finished ahead of Jennie, Nikki, Richard and Aisleyne but lost out to eventual winner Pete Bennett.
A live S4C broadcast was held on Friday evening in Glyn's home town attended by hundreds of well-wishers.
During the final live eviction, Glyn saw sales adviser Jennie Corner, 18, model Nikki Grahame, 24, waiter Richard Newman, 33, and third-placed Aisleyne Horgan-Wallace, 27, leave the house after a public vote.
But he eventually fell at the final hurdle, losing out in the race for the £100,000 top prize in a head-to-head contest with Pete, 24.
Glyn exited the house singing Whitesnake's 1980s hit Here I Go Again, before telling presenter Davina McCall he had "grown up" in the house.
Londoner Pete Bennett won the £100,000 first prize
He said fellow housemate Lea was "the most attractive person I've ever seen in my life" adding that he could now cook "boiled egg, pasta and spaghetti on toast".
Glyn, whose first language is Welsh, said it had been difficult speaking mostly in English in the house but he "got used to it".
Before going into the house he said he "just wanted everything to be Welsh, but now I want to see the world and different people".
The teenager also received a message from Welsh First Minister Rhodri Morgan which read: "Your passion and love for our country and language has been an inspiration for other young people and you've certainly put your home town of Blaenau Ffestiniog and Wales on the map.
"Your conversations in the house with Imogen have certainly raised the profile of the Welsh language to a new audience all over the world."
The message ended with Mr Morgan wishing Glyn luck in university and his future career.
In the early days of the show, Glyn was given a telling-off by Big Brother for speaking Welsh with fellow contestant Imogen Thomas from Llanelli.
Later Welsh-language conversations between the pair were broadcast with a subtitled translation.
A live broadcast was held in Glyn's home town
Imogen narrowly failed to reach the final week of the show's seventh series and was voted out of the house on 4 August.
Glyn was studying for his A-levels when the series began and missed exams to enter the house.
On Thursday, Glyn received his exam results - an A in art and design and Es in English and Welsh.
Big Brother told the teenager he had secured a place at Bangor University, and the ex-head boy plans to become a Welsh teacher.
'Lost for words'
Hundreds of well-wishers were at the S4C show in Blaenau Ffestiniog, including Glyn's head teacher and Imogen's father and brother.
One friend, Ben Hamer, said: "I think he's done well for the whole of Wales and not just Blaenau.
"He said he wanted to be the first, or second, Welsh prime minister, but he's done well."
Another friend, Idris Williams, said: "I think he'll be very shocked with all of the support he's got - outside Wales as well.
"I think he'll cope very well with it. I think he's mature enough."
Glyn's mother, Ann Wise, said she was looking forward to her son's return from the Big Brother house.
She said: "I'll just be glad to see him now - I'll probably be lost for words.
"I'll just probably say well done."