The Rail Bridge Restaurant in South Queensferry is the best place to eat and see the Forth Rail Bridge. It is very easy to reach from the railway station or the nearest bus stop and it offers wonderful views of both bridges.
What is more important is that the food is just phenomenal. (And really cheap!) A main course and a desert plus a drink for two comes in at around £30. Great deal!
South Queensferry Food Recommendation
Since it is a seaside town, best to eat fried haddock with chips and a fruit juice. If you are not a fan of fish and chips, try the steak pie with chips and Pepsi. Then tuck it down with a banana toffee cake for desert.
How to Find the Forth Rail Bridge
Take the train from central Edinburgh and get off at South Queensferry. The restaurant is less than 10 minutes away.