There are so many types of oil available in the market which claim to be good for health. I want to know which one is the best for health. Also can someone tell me what kind of oil is to be used for what kind of meat or vegetables?

Well, I don't know I have heard olive oil is very good but I use canola oil for my daily cooking and i assume it's quite healthy too.
As far as meat is concerned, I think they taste best when cooked in mustard oil.

I use olive oil - it's good for frying, roasting, salads, etc. - and healthy.

Do you use olive oil for cooking all kinds of meat and sea food like crabs(especially when you want them red and spicy) too?

yes - I like Berio - and on the bottle it will say "for sauteing/frying" and it does not leave an after taste like Pompeii brand and others -

I use it for meats, fish, pasta in oil dishes, salads, everything