Some, like these Veritas planes are elegantly made, a joy to use, and look good enough to hang on the wall. They also look like they will last and last. I bought one and liked it so much that I got the second, narrower one soon afterwards.
These are detail rebate planes, and are designed for cleaning up the bottoms of slots, or into corners.
I work with small things a lot and will use them for all the things that a block plane is too big for.
Veritas tools usually come into the expensive but very good category, but these are imperial rather than metric and are being discontinued so I got them for half price. Having tried them I think they are probably worth the full price (over £50 at time of writing).
I've started making use of the planes I own more lately, in an attempt to reduce the amount of sanding I do - and it seems to be working, long shavings don't get into the lungs, and they are easier to sweep up.