In your case i would watch all K-1 world max(especially from 2002 to 2009) and K-1 World GP(1993 to 2010),K-1 at his peak was the gold days of kickboxing in terms of competition fights and fighters.
My favorite fighters from the k-1 max gold days:
K-1 Max(until 70kg)
-Masato(one of the most exciting fighters ever,super fast boxing combinations+ low kicks,one of the 4 man to be k-1 max champion twice)
-Albert Kraus(one of the best boxing skills translated to kickboxing
-Buakaw(the most famous kickboxer-MT fighter from today and one of the most famous ever,watch his kickboxing fights on his prime 2004-2009,he used to be superfast,could kick with both legs all time,smart fighter,insane evasive skills,very good jab,one of the most dominant at the time,historic first man to be champion twice on K-1 max,one of the 4 man to be k-1 max champion twice)
-Andy Souwer(One of my favorite fighters ever,the king of punch combinations+ brutal low kicks,smart fighter,one of the best overhands on the sport,he always waited for the right time to attack ,clinic high kick precision,he used to fly with that jumping knee in this prime,he was just amazing in his prime,one of the 4 man to be k-1 max champion twice)
-Gago Drago(another one of the most exciting fighters ever,i miss hard this guy,very agressive fighter,one of the most accurate spinning kicks on the combat sports,he always entered on wars winning or not)
-Mike Zambidis(A legend on the sport,one of the best boxing skills ever showed on a kickboxing ring,his agressive fight style could neutralize bigger guys than him,small guy but very very powerful and is another one who used to fly with his knee over opponents face)
-Artur Kyshenko(A guy who i miss his fight style in his prime,who changed a lot since he entered on mikes gym,this guy was incrible on his prime,terrific body puncher)
-Yoshihiro Sato(the taller one,based on MT skills,a heavy knee+kick combinations,he destroyed a lot of guys on his days,one of the best chin on kickboxing,this guy could take a lot,but a lot of punishment)
-Yuya Yamamoto(another one who used to bring the hell to the ring,do or die style)
Giorgio Petrosyan(he entered on the tournament at 2009,when k-1 max was going down with his biggest star masato retired,this guy is the close of perfection,he only do the basic on his fights,jab+cross mid and high kicks,but he execute all of that with perfect timing,speed,evasive skills who made him the most dominant kickboxer at 70kg ever)
Most memorable fights of k-1 max old days(on the k-1 world max tournaments or not):
Masato vs Albert kraus all 4 fights(historic rivalry who grow up the k-1 max popularity since that)
Buakaw vs Masato their 2 fights(first one in 2004 and the last in 2007,their rematch was one of the most waited kickboxing match ever,two fantastic fights especially the last one)
Masato vs Kid Yamamoto(at 2004,one of the biggest fights on k-1 era,the Japanese superstar of kickboxing vs the Japanese superstar of MMA in japan)
Masato vs Kohiruimaki(especially the second fight at 2006,another of the most waited rematches on k-1 max,Kohi defeated masato on his second pro fight and masato had his chance to reveng 8 years later)
Masato vs Artur Kyshenko the 2 fights(they fought twice in 2007 and 2008,two of the best fights on kickboxing history,especially the last one on the k-1 max 2008 final)
Masato vs Kalakoda(Masato shutting Kalakoda mouth on this one,who said he was a bad boxer,only could kick)
Andy Souwer vs Masato Trilogy(3 historic fights,at 2006,2007 and at masato retiring match on 2009,the fight at 2006 was absolutely fantastic)
Andy Souwer vs Kozo Takeda(at 2005,andy Souwer destroying Takeda hard on this one,crazy finish)
Andy Souwer vs Virgil Kalakoda(at 2006,one of the best comeback on the sport,a very very very good fight,one of the best i ever saw)
Andy Souwer vs Albert Kraus(2003 and 2007 ,both fights of the best dutch guys on k-1 max,they both trained
together in the past)
Andy Souwer vs Mike Zambidis(crazy fight and a very crazy finish)
Andy souwer vs Artur Kyshenko all 4 fights(another historic rivalry on kickboxing all of his fights are very good)
Buakaw vs Kohiruimaki(crazy upset at the days,Buakaw as a unknown fighter against the second best japanese kickboxer on max division at the time)
Buakaw vs Masato(another Big upset,Buakaw humiliating the country boy masato)
Buakaw vs Albert Kraus all 4 fights(Big rivalry on kickboxing history,some controversial decisions but very good fights and totally clash of styles)
Buakaw vs Mike Zambidis(tottaly clash of styles,long waited match in japan at the time)
Buakaw vs Kalakoda(another clash of styles,heavy action crazy fight)
Buakaw vs Yoshihiro Sato all 4 fights(one of my favorite rivalry on kickboxing,they made amazing fights)
Buakaw vs Andy Souwer triology(probably one of the biggest rivalry on kickboxing,controversial decisions and heavy action especially on the last two fights who are perfect)
Buakaw vs Hiroki Shishido(one of the fastest KOs Ever)
Buakaw vs Giorgio Petrosyan(the clash of titans of kickboxing)
Buakaw vs Holzken two fights(crazy how buakaw made Holzken look like a noob in their two fights)
Buakaw vs Andre Dida(another one of the crazy comebacks on k-1 max)
Giorgio Petrosyan vs Andy Souwer two fights(Giorgio making souwer look like a noob on the last fight)
Giorgio Petrosyan vs Dzhabar Askerov(perfect performance by petrosyan)
Giorgio Petrosyan vs Albert Kraus(both of their fights showed an impressive domination and skills of petrosyan)
Giorgio Petrosyan vs Yuya Yamamoto(Destruction way)
Giorgio Petrosyan vs Mike Zambidis(heavy action)
Yoshihiro sato vs Yuya Yamamoto two fights(2005 and 2010)
Yoshihiro Sato vs Tatsuji(two fights)
Yoshihiro Sato vs Yasuhiro Kido(another of one of these crazy comeback fights,incredible fight)
these are the fights who i remember who i most enjoyed on the old days,watch all that you can,i am sure you are going to love all of them