Which is better - visa or mastercard?

I think its country specific. Visa i do know has a bigger network and as such is easier with the ATMs. For online transactions I would say it's Visa based on my experiences.

There is isn't much difference in what Visa and Mastercard are offering. however since you like using MC due to the ease with the ATMs, you can opt for a Visa virtual card (or visual MC for that matter) for your online transactions. Just better and really helps in reconciling your expenses to have one card for your regular use and one dedicated entirely to your online transactions.

is there much difference in what they both offer? i've seen thier acceptance almost equally everywhere. visa and mc both do the same jobs and there isn't any difference between them . why would anyone chose mc and not visa or would he choose visa and not mc ? anyone maybe can aquaint us any major differences between the both

I am using MasterCard too, VISA is supposed to have a bigger market share though MasterCard is a bit easier to use, as you stated.