I'd say Leach, mostly since we could've hired him 4 times: 2008, 2009, 2012, 2017. He's always viewed Tennessee as a top 5 job and it's a place that would suit him well (unlike some top tier jobs, such as USC). I have no issue with the Pruitt hire, but I was clamoring for Leach all the way back in 2008, when we could've easily brought him in and kept John Chavis as DC.
For some reason, there's a large contingent of Leach doubters here, but I find it foolish. Leach has been doing more with less for years. No, he hasn't won a national title, but Nick Saban wouldn't be winning national titles at Wash State or Texas Tech either. The idea that Leach's system wouldn't translate to the SEC is garbage. It's translated to the NFL! It's now rare to see pro teams that aren't passing the ball at least 70% of the time.
Still insane to me that no top tier program has hired him, but a lot of it is politics. Leach is very independent and fans love him, which is something that a lot of ADs and boosters don't like; a coach that they can't control.
Not to dwell on it. Pruitt is the coach and that's all that matters, but I think if Leach were hired back in 2008, he would've won a national title here.