I've grown, or at least attempted to grow most things over the last few years. My gardening philosophy has been distilled to the following:
Grow things that are relatively expensive to buy, yet easy and plentiful to grow. Pak Choi, Rocket, Soft fruit.
Grow things that taste so much better when home grown. Peas, runner beans, tomatoes
Avoid things that are cheap to buy/ or otherwise not worth the space/effort. Carrots are pennies for a pound at the greengrocers. Yet they take up a fair amount of garden space, and are prone to pests like carrot fly. Therefore not worth the hassle, when that same piece of ground could have been used for rocket & other salads, saving maybe £5 a week in shopping and providing spare rocket for a few big jars of pesto.
Avoid things that are dependant on certain weather conditions, because the weather will do exactly the opposite. Aubergines and sweet peppers were disasters for me due to damp conditions and a lack of sunlight.