Ok so here's some quick and dirty numbers on the best and worst in the Pac:
USC's best since 1960 have been:
John McKay: 127-40-8 from 1960-75 (73%) He was 8-11-1 his first two years taking over a mediocre program that already had high expectations (I looked briefly at Howard Jones. He left a lot to live up to.) His only other average seasons were 1970 and 71, which were both 6-4-1 and led up to a 1972 team that's among the all-time bad-ass units in college football history. So over 4 of those 16 years he was 20-19-3. If you didn't catch him during a 'down' year, you lost. 107-21-5 is a godly 80% over 12 different seasons, 4 of which ended in a national title. Won big, won consistently, improved the program from where it was, etc.
John Robinson: Took McKay's program and kept right on truckin' in the '70s, going 67-14-2 from 1976 to 1982 (81%). Take a look at those rosters from '76 to '80 sometime. There was a drop-off after that, and his second go around in the '90s was less impressive, but he also took over a program going sideways under Larry Smith and won two conference titles. His overall mark is 104-43-4, also 73%. He was also 7-1 in bowl games, undefeated in the Rose.
Pete Carroll: Supposedly their 4th choice (after Denny, heh, Belotti, and Mike Riley... shame Denny didn't say yes in retrospect) Carroll opened his first season 2-5 and then tore it up, going 95-14 (not counting the vacated stuff from violations) before moving on to Seattle. Win % of 84, was an insane 82-9 from 2002 to 2008 (90%), won 2 titles, and never finished lower than 4th in the polls over a period of 7 years.
These three guys are the standard in the Pac. To me Carroll is probably most impressive because of the scholarship limits that the '70s teams didn't compete with, but he and McKay both started with relatively ramshackle situations by USC standards.
Carroll followed their worst coach, our aforementioned Paul Hackett, who started ok in '98 but by 2000 was in last place in the Pac, an impressive feat. He did, however, start the talent collection that Carroll continued. Whether he could've gotten remotely what Carroll did out of them is highly unlikely. He got bounced after that last place finish and a 19-18 overall record.
UCLA since 1960:
--Just an aside, the Bruins also had a bad-ass coach immediately prior to this era in Henry Sanders, who won the school's only national title ('54) and owned SC during his tenure.
The Bruins get two entries for top coach: Tommy Prothro (who they lured away from Oregon State) and Terry Donahue. Prothro was 41-18-3 over six years from '65-70, a 66% mark. Prothro may be one of the most high profile victims of officiating burnout, leaving UCLA for the nearby Rams after getting repeatedly burned by freak calls in big games or not getting bowl invites because of the Pac 8 rule about conference champs being the only ones that went.
Donahue was a Vermeil assistant that got bumped up to the top job when Dick went to the NFL. His overall mark of 151-74-8 matches Prothro's win % (65) but sustained over a much longer period ('76-'95). '82-88 was Peak Donahue, as he and Don James at UW took advantage of USC's relative downturn and turned it into conference titles. He was 7-0 in his bowl games during this stretch and consistently hovered around the top 10, but his best shot at a national title was blown when he lost to WSU and USC in '88 (probably would've lost to Michigan in that Rose Bowl too, they were as good as ND and Miami that year and played both tough).
Worst UCLA coach is... *drumroll* Neuheisal. Bob Toledo was more Price-esque (feast or famine), Dorrell and Mora were mediocre, but only Rick carries the distinction of a losing record in the last 50 years of UCLA football, going 21-29 over 4 years.
Oregon State is an interesting case, in that perhaps their best ever coach gave his best years to a rival Pac school, and his replacement turned the program into a wasteland unmatched anywhere outside the state of Kansas (or maybe the city of Chicago) for years and years. Prothro was 63-31-2 from 1955 to '64, winning 3 conferences titles, a Liberty Bowl as an independent, and made 2 Rose Bowl appearances. Nobody else since has managed a resume' like this. Only Mike Riley (103-66 has sustained success, and only Erickson (31-17 4 years) managed a conference title.
Dee Andros has been cited above as the saboteur of all Beaver fan happiness for a generation. He got an interview after impressing Beav people for a scrappy game he gave them in Prothro's last year coaching an outgunned Idaho squad. His overall record of 51-64-1 isn't that bad on the surface, but the trend was down, hard, his final 5 or 6 years. There's no way a coach would be allowed to continue on this trend for as long as he did in the modern game, really. From '65 to '70 he was 32-22-1 with 3 straight 2nd place finishes from '66 to '68. He was 5-6 in '71, and then the bottom fell out. He went 8-36 over 4 years from '72 to '75, and his successors from Fertig through Pettibone were a combined 44-183-5 from '76 to '96, for a 19% win rate. So imagine getting Paul Wulff results for 24 straight years. That's what Beaver fans suffered. Avezzano had the worst stretch from '80 to '84 (6-47-2) but as Flat pointed out, does that make him the worst qualitatively too? Hard to say in this mess. What Riley and Erickson achieved here is pretty remarkable. Like Bill Snyder remarkable.
I'll post on a few more teams later this week when I might have the energy and inclination.