- a bank transfer (SWIFT/SEPA/WIRE)
- a credit card (debit card - visa or mastercard)
- cash
- a PayPal account
First thing to consider - what's the fee you're being charged for each payment channel? Credit card and paypal is likely to the be the highest. An ACH transaction from a bank account may be cheapest.
Second thing to consider - time it takes for the purchase to settle, meaning how long until you have access transact/spend your purchased bitcoin. Credit card will likely be the fastest/shortest settlement timeframe. Whereas bank transfer would be the longest, wires just take days.
Third thing to consider - as you stated are what other options exist? What about ATM deposits/purchase? I would think this would be the fastest and safest and cheapest route, but I've never used one. They're still really new, right?