Well, the option i would choose isn't in the poll, so i'll explain it here.
I would like something similar to New Vegas, were the main quest is more of a big objective for your whole adventure, rather than a single quest-chain to check on my ToDo-List.
In New Vegas the main quest line was first about teaching you the world and the factions, which you did naturally as you travelled the mojave, and afterwards aimed towards the second battle of hoover-damn. Depending on your choice of faction you would be send to various smaller factions, to either convince them to join you or get them out of the way.
I really liked this, because it gave everything a sense of purpose. Doing the major sidequests for a subfaction wasn't always required to get the main quest moving, but it still felt like doing these additionall sidequests helped you achieve your overall goal of preparing for the battle. These sidequests didn't have a real big impact on the battle itself, but it still felt like doing them did something towards achieving this higher goal. I always end up doing pretty much every sidequest and it just feels better doing them when you have the feeling that it helps you achieve some greater goal in the game. Even if it doesn't end up having an impact, the feeling is what counts.