I have a US bank account and debit card, and I am trying to buy bitcoins instantly. So far I have found Circle as a great option however there verification process is taking forever.
Do you guys know any other sites where I can send in money and get my bitcoins within a day?
I think Coinbase, Circle, and Kraken are all good options... trustworthy and reasonably secure thus far, with significant VC backing.
That said, if you're relatively new to Bitcoin and you like to keep your coins in those wallets,
I recommend using all three -- plus Blockchain.
It sounds like you're investing, so it's ideal to diversify in order to reduce specific risk (i.e. your main wallet company Gox'ing).