Geek Squad is okay. It's fairly stressful work for a couple of reasons:
1. You'll never have enough time to be completely thorough on each machine, and the people who demand you go faster have absolutely no clue about the amount of work that goes into diagnostics.
2. Your true job is that of salesperson, not fix-it guy. You will spend 90% of your interactions with management being taught and tested on how to sell things like anti-virus programs and cleaning services, and 10% of it on how to do the technical side of your job.
3. Geek Squad members are almost unanimously the most socially retarded of all employees in retail. Don't expect a lot of stimulating conversation (but you may get lucky) - but you can always hang out with the rest of your coworkers.
For all that, it's still quite possible to have a lot of fun. Your coworkers undoubtably won't take their jobs very seriously, so everyone is fairly laid back when management isn't two feet away. And sales, even the kind where you have to exert a lot of pressure on the customer, can be a lot of fun. Give it a shot - it's not as bad as everyone says.