I just felt like writing some of the best Jarl trades in the Season Unending quest.
Winterhold-Trade Jarl Korir for Kraldar, since Kraldar is not racist, and doesn't have a problem with the college of Winterhold. (Stormcloak to Imperial)
Markarth-Trade Igmund for Thongvar Silver Blood, since Igmund is sort of unlikable (In my opinion), and the Silver-Bloods already basically own The Reach. (Imperial to Stormcloak)
Dawnstar-Trade Skald the Elder for Brina Merilis, since Skald is kind of old and grumpy, and Brina is friendly, even before the quest. (Stormcloak to Imperial)
Riften-Keep Laila Law-Giver as Jarl, since she actually tries as Jarl, and Maven Black-Briar would just get spoiled again, which she is used to. (Stormcloak)
-Lastly, don't forget to kick Elenwen out of the council.