Disclaimer: I started at Goldman so I am biased but...
Goldman Sachs is by far the best place to start a career. They usually pay the average or just under because they don't need to pay a premium to attract young talent. Having Goldman on your CV will open doors that were previously closed and will increase your market value immeasurably.
That said, JP Morgan is also a reputable institution but as I said, I am biased.
Ultimately, look closely at the team that you are going to join. Use the team to be the ultimate deciding factor for which institution you go for.
(The) Girl Banker