Two old favorites of mine, somewhat battered books I found at a library book sale a while back:
What If a Lion Eats Me and I Fall into a Hippopotamus' Mud Hole? by Emily Hanlon with pictures by Leigh Grant
This one is a favorite standby, partly because I am a big worrywort & I never find that old piece of advice "Think of the worst thing that can happen and you'll find it's not so bad" very helpful--I can always think of something that is plenty bad, thanks just the same. Ditto for the sort of helpful advice the kid in this book is trying to provide--for every way out, there's an equally bad "What if?" just waiting to pounce. On the other hand, sometimes it does help to think "What if my daddy buys us a hot dog, popcorn, and ice cream?" Occasionally, I even think it in those terms. It makes me smile, and then I can go on and do whatever.
The Star Thief by Andrea DiNoto, with pictures by Arnold Lobel: Nothing profound to say about this one, it just makes me smile.
And, yes, I probably should see what else these folk have written (in both cases, the illustrations are fine, but it's the stories I love). It might turn up some more unexpected gems.