I'd say go with your gut instinct. Both unis are very highly rated so a degree from either will be great. I was in a similar position and had to choose between Keele and Durham. Durham was higher up the league tables but I loved the atmosphere at Keele and , like you, much to my dad's annoyance, went there. I had the best time of my life.
You will be living there for three years, so your choice is about more than whether the course is right for you - it's about developing as a person and getting to make friends.
Since I left Keele I've done a masters at Leicester and have a high-flying career. I was happy at Keele and got a great education.
Sheff is a fab city and is highly rated compared to most other unis. To be honest, I don't think most employers know where the majority of unis stand in the league tables.
Go to Sheff - great people, great city, great uni! (BTW one of my cousins did psychology there - she's now a millionaire living in Switzerland with several recruitment consultancy businesses!)
Good luck - wherever you go, you will have an amazing time!