We have integrated PayPal, BitPay, Paysera (for Webmoney, CashU payments) and currrently working on Credit Card payments. You should really look what payment methods your audience is using and then choose them.
For Indian Clients, we use EBS and PayUmoney payment gateway. Both the payment gateways support credit card, debit card, cash card, rupay card and netbanking payments. For international client, we use PayPal. We had a bitter experience with 2Checkout.
PayPal, Bitcoin, Skill, Payza and Perfect money is my payment choice.
Main payment option for any hosting company is PayPal. If you use any other payment gateway then your site must be listed on #10 result of google for your selected payment gateway to receive many orders otherwise your company will be not get to much order.
Many payment gateway options are available, and each payment gateway has its pros and cons. Some the payment gateways have less subscription charge, but their transaction commission is on the higher side. Some the payment gateways are economical but may lack some features. We use debit/Credit Card, PayPal, Bank Wire Transfer, Moneybookers and Worldpay, etc.
We've been operating for a long time with PayPal as our only gateway but will be rolling our 2checkout and then Stripe for credit/debit card soon. I don't really think you need any more than that, normally a merchant card account plus PayPal is enough to get you by.