I'd be all for the Stormcloaks if it wasn't for the fact that the Stormcloak Jarls throughout Skyrim seem to all be paranoid, corrupt and/or spineless. The only Imperial Jarl that I really have an issue with is Riften's Maven Black-Briar, but the Stormcloak Jarl alternative is basically in Maven's pocket anyway, and thinks her own son is mentally deranged simply because he disagrees with Ulfric.
Honestly, I love the idea of a free and independent Skyrim and would support that, but not with the leadership that the Stormcloaks bring to the table. I can't see a country in the process of establishing itself as independent benefitting from such poor leadership. The Empire is just the lesser of two evils, in my eyes.
Well, to be blunt, none of the original Jarls are very good.
Supporting Elisif:
-Ravencrone, who I personally like a lot but apparently is so caught up in her visions that her own housecarl thinks she needs to step down.
-Igmund, a generally incompetent Jarl who doesn't seem to understand the Forsworn problem(and before anyone starts about Igmund, the guy who sells horses at the Markarth stables says Igmund's dad was the one who arrested Ulfric, which means he almost certainly was the one who ordered the execution of Braig's daughter and others, not Igmund. Igmund speaks as if he was there because he probably was. Based on his looks, he was in his late teens/early 20's during the Markarth incident, old enough to understand what's going on but not in any real authority.)
-Siddgir, who drains the entire Falkreath treasury on mead and clothes, doesn't even pretend to run his hold, and cuts deals with bandit groups.
Supporting Ulfric:
-Skald, a bratty man-child who thinks the dragons are Talos' wrath(I find this especially ironic since through my playthroughs Dawnstar has suffered more dragon attacks than every other city combined).
-Korir, a guy who actively campaigns against the only reason his city has to exist anymore, and actively encourages racism against elves in his son.
-Lalia, whose heart is in the right place, but has nothing between those ears of hers.