Not a direct answer to your question, but IMO, one of the best investements to make for someone who likes to cook is in books that teach techniques rather than just (or even) give you recipes.

That makes all the difference in the long run. Mastering the basics (and having a reference to them at need), makes you far more confident and adventurous in the kitchen than faithfully following recipes for years, never too sure why it's done like this, or if it's ok to skip that, or to substitute this and so on. You get far more confident in dealing with recipes, and use them more as guidelines or inspiration, and improve them to fit your tastes and instruments, and to fill in the gaps or correct mistakes. It makes cooking a lot more fun, because you're far more relaxed and confident.

Julia Child or Anne Willan (I have both) would be good examples for French cooking, though books like this exist for most traditions/cuisines, and for specific techniques. The Silver Spoon is a good one for Italian cuisine. Solomon for Asian cooking in general (though I prefer cuisine specific for Asian cooking, Suzuki's Japanese Homestyle Cooking is one of my favourite cookbooks)

Just one, I might pick "Modernist Cuisine: The Art and Science of Cooking", not that I could afford it @ 450 US$ (and it's really a bible for pros, that one).