To me the silliest barroom/message board discussions related to sports are the sometimes passionately-argued debates about which of two conferences is "better". While there are some legitimate contexts where conference affiliation matters, they rarely relate to things that correspond to challenging a fan's manhood, or insulting someone's momma.
These are especially silly when applied to Division-1A football, where in most contexts there just aren't enough data points (games) to make any kind of objective measurement. Not that that stops people from using measurements that work fairly well in sports with more interconference games to buttress their "case" - there are enough of those that you can make a case for any randomly chosen conference just by picking the right measurement, but that doesn't make the case any more useful.
All of these arguments pretty much sound like nine-year old boys at recess. As many kinds of "evidence" as there are, they pretty much fall into just a few categories.
This one can provide some objective measurements that are useful for comparing conferences if one is careful with the definition. It is still a little vague because not all conferences have the same number of teams, but if you take, say, the bottom six teams from each conference and add their records you can come up with a "cootie index". The more "bad" teams a conference has, the easier the conference schedule is for its "good" teams. Math comes into play a little here, too - in any given year every conference with ten or more teams is likely to have three or so teams in the bottom quartile just by chance and the fact that for every win there's a loss. Depending upon where you place the cutoff (worst 6? worst 5?, worst 4?) the conferences look more or less the same. Nonetheless, this is probably a better "based on the results on the field" measurement than the others (if one is careful).
When fans find themselves on the short end of the "cootie index" measurement, they resort to the most useless argument of all...
What they mean is that they don't need any stinking comparisons based upon any one sport, they are sophisticates who "understand" that there's more to a "conference" that what its football teams do. They are mostly correct, when one starts looking at things like the above considerations for more than one sport, or such off-field issues as academic standards quality of fan support for ugly little sisters, etc. the concept of what a "conference" really is gets clearer. But one always gets the idea that they started life as the skinny little kid with glasses who, although he always got beat up by the neihgborhood bully, really was smarter than everybody else. He is therefore distrusted. He either will grow up to be a lawyer or a CEO being sued by a lawyer for accounting fraud.
All of these fall into the "Well, our cheerleaders are prettier than your cheerleaders" category. (Notice that girls no longer have cooties). "We have more fans", "We have more passionate fans" (these nerds know that momentum = mass x velocity - no, wait, I meant dollars = number fans x ticket price). All of these kinds of arguments tend to be more objective and factual than the ones the nine-year-olds present, but are just collections of facts that have no intrinsic meaning and therefore no objective interpretation.
There's one more "serious" comparison that is used by people who sound like they know what they're talking about, but really should know better: the conference vs conference record.
It certainly sounds right when they say that the only way to judge a conference is by interconference records. But this is no more true in football where there aren't enough data points to justify the statement than it is in, say, basketball, where there are a lot more data points. In fact, these same folks who sound like experts will tell you that the SEC's obscenely high interconference winning percentage in the 2004 baseball season is due only to the SEC teams playing weak opponents (true enough, by the way) say that the same measurement does apply in football where only the weakest SEC teams lost to strong (and weak) opponents.
The best team in the Big 12 beat one of the best teams in the MAC. The absolutely worst team in the SEC lost to one of the worst teams in the Big East. That's an 0-2 swing in what the people who want to use this metric say is "indicative", but there is no way to conclude from those specific results that the best team in the Big XII would beat the best team in the SEC. All you can tell logically is that you can't tell anything from those results (or any like them). There are ways to sort these out so that interconference records are adjusted by which team played which team, but those require more sophistication than these "sounds like experts" use, and very much more sophisticated than most barroom or internet board posters can explain.
The one case where conference comparisons are useful is in determining the field for post-season play. Interconference records are not very helpful: if team A plays team X and B plays Y, there is in general no inferences that can be made about the relative rank of team C and team Z. But, if team C and team Z are being compared based upon their records, it is worth knowing how much their conference record should be worth. A legitimate way to do this is to count the number of ugly little sisters.
The preponderance of weak teams in a conference is an indication of how easy it is to have a good record within the conference - the games that are scheduled by the league office and not the teams. This does not mean that the conference teams A and B came from is "better" or "worse" than the ones teams X and Y came from, but it provides some useful information for evaluating teams C and Z relative to their records. Not a great deal of information at that. For example, a 6-2 team from a conference whose worst six teams have a combined winning percentage of .413 probably had a harder time getting to 6-2 than a 6-2 team from a conference whose six worst teams went .339. Does that mean the former conference is "better" than the latter? Of course not, it's just some useful information.
And in 2004 one of the bits of information that we get from the cootie index is that the SEC has the ugliest little sisters of any BCS conference with 8 or more teams (actually, there's nearly a tie between the SEC and Big 10). So obviously anyone who publicly pronounces that it is "harder" to go undefeated in SEC conference play than any other is clearly appealing to the "Grandfather won the war" argument.