Here is a collection of players who have been influential in the competition's 15 years:
Shane Horgan (Leinster)
With 39 tries in Leinster colours, Horgan has crossed for more Celtic League scores than anyone else from the province. The 6ft4 winger was man of the match during the competition's inaugural final, bursting through Munster tackles and scoring one of his many tries. He was fourth on the league's try-scoring charts as Leinster won their second title in 2008.
Dan Parks (Glasgow Warriors/Cardiff Blues/Connacht)
A ruthless accumulator of points, Australian-born outside-half Parks holds the all-time points scoring record with 1582, including a remarkable 41 drop-goals in 171 appearances. The Scottish international can also claim the record for most points scored against Edinburgh, Munster, Newport, Ospreys, Scarlets and Ulster. He has also scored more drop goals for Blues, Connacht and Warriors than any other player.
Marco Bortolami (Aironi/Zebre)
A once-in-a-generation lock, long-term Italian captain Bortolami was man of the match weekly during his time with Gloucester, but it was a move to Aironi and then Zebre which revitalised his international career and he has been integral in the development of Italian rugby for over a decade. He will be remembered as a GUINNESS PRO12 and Italian great.
Gethin Jenkins (Cardiff Blues)
Wales' record cap-holder has been a Blue for the vast majority of his 16-year professional career and came within a whisker of league triumphs in both 2007 and 2008. The evergreen Blues captain never quite settled away from Cardiff and despite a lengthy injury history, has made 95 appearances for the Welsh club. As competent over the ball as he is destructive in the scrum, he is the archetypal modern-day loosehead.
Alastair Kellock (Edinburgh/Glasgow)
Former Scotland skipper Kellock was the ultimate club man and was praised universally for his remarkable leadership. In Scotland colours, he led his country to their famous 2009 autumn victory over Australia, while he was Warriors club captain during their maiden title winning season in 2014-2015. Despite facing stern positional competition from Leone Nakarawa and Jonny Gray, Gregor Townsend knew Kellock's experience was vital to their success.
Stephen Jones (Scarlets)
A title-winner with Scarlets in 2003-4, Jones had a two year stint with Clermont Auvergne before returning to GUINNESS PRO12 action with the Llanelli-based side. Jones amassed 741 points in 77 games for the Welsh region, was Welsh cap-record holder when he retired and is now backs coach for the Scarlets.
John Muldoon (Connacht)
With over 200 GUINNESS PRO12 appearances, Connacht captain John Muldoon has seen his region go from perennial underachievers to title-challengers in his 13-year career and with 15 appearances already this season, the stalwart is continuing to build on his legendary status in the west of Ireland. If league-leaders Connacht go on to clinch the title Muldoon will join the pantheon of great Irish captains.
Alessandro Zanni (Benetton Treviso)
Iconic back-row forward Zanni has made 58 GUINNESS PRO12 appearances for Benetton Treviso since his move from Calvisano in 2009, scoring six tries. However it is the current captain's talismanic status for Treviso which stands out and having signed a long-term deal last season, he is set to continue as the lifeblood of the Italians for years to come.
David Humphreys (Ulster)
Ex-Ireland fly-half Humphreys will go down in Ulster folklore as both player and coach. He captained them to European Cup success in 1998-99, accumulated 786 league points and with the Ulstermen at risk of squandering a slender league lead when two points down to Ospreys in 2006, his 40-metre drop goal clinched the title with four minutes remaining.
Shane Williams (Ospreys)
Old twinkle-toes himself, Williams crossed 34 times in 92 Celtic League games for Neath and later the Ospreys. Wales' record try-scorer finished a remarkable club career in typical fashion. First he scored past the 80-minute mark in his final appearance at the Liberty Stadium - even converting his own try - then he scored in the 78th minute of the PRO12 final against Leinster, with Biggar's subsequent conversion snatching a 31-30 win.
Brian O'Driscoll (Leinster)
The great man lit up the Celtic League for 14 years. A fiercely loyal Leinsterman, O'Driscoll was the linchpin of Leinster's ascent to the head of European rugby's top table. He was integral to Leinster's record-equalling four GUINNESS PRO12 crowns, which witnessed the lightning quick former Blackrock College youngster who dazzled defences become a grizzled, turnover winning talisman.
Dan Biggar (Ospreys)
At only 26 the Welsh fly-half has already turned out 129 times for the Ospreys and with 1374 points, Biggar is rapidly approaching Parks' all-time record. Long underrated, he came through the club's academy to make his debut as a teenager, was the youngest Osprey to make 100 appearances, has been part of two of the region's four title-winning teams and kicked a last minute conversion to clinch the 2012 crown.
Paul O'Connell (Munster)
Along with O'Driscoll, he is an all-time great. The leadership that carried him to the captain's armband for Ireland and the Lions was established in a Munster side that clinched three league titles, was three times the runner-up, and twice won the European Cup. Destructive in the loose and masterful at the lineout, his performances in red will live long in the memory.
Taulupe Faletau (Dragons)
Tongan-born No.8 Faletau is a product of the Dragons' highly-successful youth system. He made his Dragons debut at 18 before an international cap followed at 20. He has made 70 Dragons appearances since 2009 and has consistently impressed with his direct ball carrying, becoming the league's most ruthlessly effective No.8.
To buy tickets for the GUINNESS PRO12 Grand Final click here. Also follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the GUINNESS PRO12.