There have been some positional duels in the Prem this season that caught my eye (leaving aside last place, that was nailed on for some time!)
You obviously had the the battle for top, which went to the wire. But also it seemed that whilst 3rd spot looked confirmed for a while, other teams failed to take advantages of the slip ups. Chelsea and Arsenal seemed to make hard work of it, and ManU might have briefly flirted before the new manager bounce wore off. All three were surprisingly inconsistent. Then you had 7th spot, which nobody seemed to want. It looked like Watford's to lose but maybe they decided to rest up for the FA Cup.
Edit: more on this. Folk spoke at first of this season as being 'top 6' and 'best of the rest'. In fact we've seen a greater fracture than this. It's been top 2, then a group of 4, then another larger band followed by those that struggled from day 1. As the season went on, there wasn't a great deal of interchange; it largely stayed battles within battles. West Ham seemed to have a late surge that defied this but other that that, I reckon teams pretty much stayed in their groups.