Seems there's some disagreement with my listing. So, i'll be a lamb and provide a brief comment to justify each ranking.
1-Crawford: Undefeated, reigned Supreme at 135, dominating the other champs (burns, gamboa) then at 140 dominating the champs (dulorme, postol and ndongo), olympic gold medalists felix diaz and top contender beltran. Nobody in boxing currently has accomplished more.
2-Rigo: undefeated, dominant at sbw. shutout pfp guy donaire in rigo's 11th pro fight. dominated rico ramos and joseph agbeko
3-Lara: although his record doesn't show it, lara is, IMO, an undefeated fighter. he beat williams and canelo. Other than that, he has dominated the likes of ishe smith, austin trout and terrell gausha.
4-Errol spence: undefeated...still rising up in the rankings, but by wiping the floor with algieri and brooks, two championship caliber guys (i consider brook to be an elite fighter if not pfp who would have beaten thurman), proved he's the best ww on the planet.
5-Danny Jacobs: I rank danny jacobs over ggg because IMO, he clearly beat ggg even though he didn't get the decision (boxing politics). I rank him #5 pfp because he proved to me by beating ggg (by a fairly comfortalbe margin) and KOing quillen in one round, that he's the best mw on the planet. I don't hold his other loss against him as he was dealing with a personal tragedy and also in the early stages of cancer. IMO, if you throw out the ggg loss as a gift (which it was) and the pirog fight due to his personal and health issues, he's an undefeated fighter.
6-Thurman: Undefeated. the best ww next to spence. unified the title and beat other champs such as porter and garcia in their primes.
7- Lomachenko: lost to salido, but came back with solid wins over russell jr and nicolas walters, two champs in their own right.
8- Tie: Canelo / golovkin: Canelo, IMO is overhyped. I feel he COULD have lost the trout fight and wouldn't have got the decision if he hadn't been such a big star. i also feel lara beat him fairly convincingly. Of course, floyd dominated him...but canelo also has had some success. wins over cotto and jcc jr and amir khan. Ggg on the other hand built a long KO streak against very questionable opposition (adama, stevens, rubio, wade, monroe, geale)...when he stepped up in class, in his last three fights he's looked very ordinary. the draw with canelo was, IMO legit....i actually had canelo winning 7-5. If canelo had fought ggg's comp, he'd look devastating too....and if ggg were to fight the caliber of guys canelo struggled with, he would have done no better. they're pretty much even.
but to be completely honest, i think jermall and demetrius beat them both...jermall and andrade just don't have the big names on their record yet to crack the top 10 pfp.
10- Gary russell jr.: Lost to lomachenko, but came back with spectacular KOs over champions gonzalez and escandon.