They’re all pretty wonderful, the key is to make a good combination with the frosting, and to select a weight/density that you like. Pound cake and genoise are both wonderful yellow cakes, but are as far apart in weight and texture as any two cakes can be.
The golden Genoise is my favorite yellow cake in the entire book, but it does take some egg foam know-how. It’s wonderful with Apricot silk meringue BC or apricot-vanilla mousseline (take a look at Rose’s golden cage!) or with lemon curd mousseline (pictured in the showcase section). And the genoise classique is extremely light, tender and refreshing, which can be wonderful paired with fruit flavors for Spring.
For butter cakes (I only use these for cupcakes), I love the sour cream butter cake paired with fruit flavors, the golden almond paired with just about anything- fruit, nut or chocolate, and the downy yellow is a lovely yellow cake base without extra flavoring like sour cream or almond. Check the sidebars for appropriate pairings, they are very helpful. I have yet to try the Golden Lux cake, mostly because when I made the white version, white choc whisper cake, there was too much white chocolate flavor for me (cake was wonderfully light and fine grained, really beautiful, but I’m just not a white chocolate person).