Del Rio was a weird case to me. The guy was pretty damn good in the ring, put on consistently entertaining matches - sometimes legit great matches - and he had a real presence to him. But for some reason, he never truly clicked with the crowd.
He was a victim of shitty booking as most WWE wrestlers are (specially as time went by, the last 2 and a half years it went from bad to worse) but he was still constantly pushed as a top guy for almost 3 years (2010-2012) and for a good chunk of that run he barely lost. I remember him being one of the few heels in E' that would win clean most of his matches.
Edge beating him at Wrestlemania in the fucking opener after winning the biggest Royal Rumble ever was beyond stupid. But IIRC, Del Rio wasn't that over at that time either - I don't remember him ever getting back the heat he had in his first few months in the company - that still doesn't excuse him losing at Mania against Edge but man, I never really understood why he never clicked. A shame.