Some (hopefully useful) basic advice.
$400-500 won't get you anywhere near a "unique" or "interesting" watch, for that money you will get a "common" watch, that however can be "good quality" and last for many years or decades.
Your first choice should be with the type of mechanism:
1) manual charge
2) automatic
3) battery driven
4) solar
#1 and #2 are mechanical and will need some periodical maintenance/repairs.
#3 will have batteries dying exactly when you least expect it (and in most cases you will need to have them replaced by a service/shop if the watch is waterproof)
#4 is today the only "logical" choice if you want something that "just works".
There are many makes of these, and countless models, with many price ranges.
Check the material it is made of (actually its weight) there are people that like "heavy" watches, and people that like "light" ones (please read as stainless steel vs. titanium or plastic/other light material).
Same goes for the wristband, there are people that want it metal, people that want it leather, people that like it rubber or other material.
You want a 100m waterproof unit (which means you can use it in any normal situation, including swimming or snorkeling).