If by CO-commentator you mean either colour commentators (the analyst sitting alongside the main caller, like Sterlo) or sideline commentators, there have been a proliferation of sub-standard ones RL fans in Australia have been subjected to with since PayTV started broadcasting matches in 1996 (with Optus, before Fox started with SL the following year).
Yes, most of them were brilliant RL players, but in Australian sport, there has always been this fixation from the tv broadcasters to hire ex-players, assuming that ex-players are great communicators and analysts...nothing could be further from the truth. RL fans deserved far better than what's been dished out over the past two decades.
For Fox Sports:
- Laurie Daley. Find it hard to believe he was Fox Sports main co-commentator (partnered alongside games Warren Smith called) during 2001-12 (excluding 2008 where he joined Ch9) until he left to coach NSW Origin. A decade of Lozza! Always hated the inflection he used to put at the end of nearly every sentence, and loved stating the obvious (e.g. "whoever scores the next try wins the game").
- Steve Mortimer and Brett Kenny. Both of them sounded very monotonous, like they were sitting in a pub and talking to friends whilst having a beer.
- Russell Fairfax.
- Gordon Tallis. Although to his credit he has improved a lot on camera since being on The Matty Johns show, he was an absolute shocker during his commentary days at Fox.
- Wayne Pearce. Voice sounded like a squealing pig. Still remember his commentary from Wests Tigers vs Canberra in 2006, sounded like he was going to burst into tears after Canberra won in golden point.
And more recently,
- Mark O'Neill, Scott Punce, Steve Menzies, Brett Kimmorley, Brent Tate, Scott Sattler and Simon Woolford. Boy oh boy, there's some shockers in that list. With all the money Fox has and have put into league broadcasting over the past two decades, surely they could've hired better talent for their RL coverage than that.
For Optus:
- Mario Fenech. I absolutely hated how he kept interrupting Terry Kennedy during the broadcast. Reminds me of when he used to keep saying "Fat!....FAT!....FAT!" when he was on the panel of The Footy Show.
For Ch9:
- Wally Lewis (thank God he was taken out of the commentary box for Origin this year). After all the years he has had at Fox Sports and Ch9, he just hasn't made the transition over to commentary. Too static and tense, like he is reading a news report in commentary.
- Phil Gould. Was very good when he used to feature as guest co-commentator whilst still coaching first-grade back in the '90s. Mainly commentated during the finals, then replaced Fatty for Ch9's Sunday game from 2001 and then became the permanent 2nd co-commentator alongside Sterlo from 2006 onwards. None of this "NO NO NO NO NO/DEAR OH DEAR OH DEAR" crap, constant negativity, getting wound up over trivial issues, contrived melodramatic disputes with Rabs etc. when he first started out back in '94. Was watching replays of Newcastle vs Canberra and Illawarra vs Canberra from '94 and he was a breath of fresh air: far more insightful, more relaxed, knew when to talk and add something useful to the commentary. Hard to believe it is the same person when you listen to him back then