Lakes are nice. But what we really need are waterfalls. Really big ones.
Yes Sir/Madame (from your name I would guess Madame, but you can never be certain). We need long, complex rivers with waterfalls and all kinds of wildlife swimming around in it. I just realized that fishing might also be a nice little feature, but that's a bit off topic. Well, this entire post is, come to think about it...
So, anyway: yes to lakes. Better ones than in Oblivion (the one that was there).