On APS-C, I find the 50mm FL: SEL35 (or the Sigma 30) to be the most 'forgiving' FL. The SEL50 is a nice FL if you have the distance, and the SEL24 is great for indoors, groups, and 'wider' view, such as architecture or landscape, but is not as dramatics as e.g. a 20mm or wider lens would be.