Riley for sure.
Usually fans have positive bias towards Warrington-born, Academy-produced talent and overhype the few that do come through. Riley never got much appreciation despite scoring a hundred odd tries, winning three Challenge Cups and holding down a place in our strongest team for decades. He never even got the hometown folk hero reputation that Mark Forster had. It felt like a lot of our fans didn't really think he was good enough and thought we could do better. You couldn't use the Fa'afili argument (he only got all those tries because of playing outside Gleeson) because most of the time he played outside Ryan Atkins, who everyone says never passed to his winger.
A few years before Riley emerged, we had Dean Gaskell, and it felt like the fans were always on his side, chanting 'Deano Deano' and willing him to make it, even though he never scored. Riley always scored tries but never had the same goodwill.
I wonder if some of it was because Kevin Penny emerged at a similar time, and most people would have preferred Penny because he was a more exciting prospect, but Riley won that selection battle as he was more consistent when Penny went through his flaky form. Possibly some fans thought that if we'd have persevered with Penny we'd have had a player with an extra yard of pace, and that Riley was like settling for the lesser option but I don't agree, Riley was better equipped to handle SL.
The other thing I really liked with Riley was he came back from being written off a couple of times. How often have we seen young players go through a bad spell of form, get dropped, sent out on loan and then their career disappears into the lower leagues. A narrative then often gets created around them that they were 'treated disgracefully' by whoever was coach at the time and they would have been a great if only we'd persevered with them. But that happened to Riley after we signed Joel Monaghan and he was sent off to Harlequins on loan, but he came back and won his place back in the team and was one of the top try scorers for the next couple of seasons. He also adapted to being moved from wing to fullback without fuss.
An excellent Wire winger