Since i dont really frequent the 1v1 scene take my opinion with a grain of salt and also my subjective opinion of myself can also be wrong and thats ok,if you feel diffrently then please feel free to trash me,im just trying to be honest.
the best playersm for 1v1 in no particular order are imo:
Godde - most agressive lacks endgame power
Randy - most stable and best macro lacks endgame power
Drone - the porc lord just pure eco and porc/arty,the weakest in early game hardest to kill in lategame
Dregs - feels similar to randy but more agressive
izyraid - its hard to understand his strengths,sometimes his plays are top line but sometimes dose not work out very well,is not as stable as the rest but i feel he is very strong when at his peak
Manu - somehow he just wins i dont know how but he dose,his positioning is very good tho,other than that i really dont understand what makes him so strong
Zenfur - very good on defensive play and overall very stable a very versitile player with proper endgame play
Helwor - (hands down the best airplayer i have seen)
Me - i think i am the most versatile,but my macro sucks
the best in casual is hard to gauge because the effectivness depends too much on the team as a whole but i think i am the best here just because of experience and history of holding back entire teams with little support.one caveheat here im talking about big teams,small teams up to 5v5 are a lot more volatile and unpredictable because every players skill matters much more than in big teams.(high elo small teams are elo farms btw)
again in no particular order:
Me - i think im very versatile (air,eco rush,dante rush,frontline,support) whatever it is we need i can do it,still i think the best i can do is frontline i usually fight multiple ppl at same time,i dont think if thres just 1 guy holding me he will last long.
izirayd - very good clusterfuck player,i think he is the best air to have(maybe his input about his feeling when we are both air)
Firepluk - no joke firepluk strats in team games are very effective,he lacks versatility because once his strat is known he dose not change it and resigns when he fails his the best wildcard to have.
Manu - i have only ever seen manu be effective as a lance user,but i think he is the best lance user in big teams
Senaven - one word,roaches,by far the best cloaked roach player ever,i have seen him hold entire teams with just cloaked roaches,and he actually kiled a screened bantha with roaches ridiculous.
Anarchid - very versatile good knowledge and can play very good air and frontline support.
Anir - when playing at his best,he can fight multiple ppl at same time and win.
Zenfur - i think hes on similar level as me in clusterfucks,but i dont think hes as consistent as me
Clusterfuck is just hard to have a meaningfull impact,so i think ppl who can get high elo only from clusterfuck are great players.most of my elo is from clusterfuck i managed to get this high must mean something.
Maybe im beeing arrogant idk,correct me if you feel diffrently and think i missed someone anyway its hard to make decent arguments in few words