You havent described some important aspects.
1) Size - Usually determined by wrist size, although not always, some people like big watches at 52mm like the sub aqua mentioned above, some dont. Some people like Tissot, low end Tag 39-42mm range watches, some dont, this is crucial to short list watches. Get an idea on your wrist size and what size watch you think will suit your wrist best
I have small wrists, ~ 6.75-7" in circumference. I'd probably be looking for a mid-size watch, as a smaller watch would look too feminine (in my opinion), and a larger one would be over the top.
2)Style - There are numerous basic design styles from classic diver style watches to modern day fashion watches with LED's. Try and decide what style suits your personality and taste, do you want an elegant dress watch, or a sporty diver watch, or a complicated time machine. Do you like a simple looking dial or one with lots of complications and tech wizardry.
I think I'd be looking for something more on the classic side, although I do enjoy fancy functions and such, I think it sometimes makes the watch too busy looking.
3) Movement - Most people who starts looking at watches seriously and starts collecting stuff move towards automatic movements. While they are in most cases not quite accurate as quartz, they offer a special charm and a sense of mechanical "wow" factor which can make the purchase worthwhile. There is tons to read up on movements, and for your price range there are some decent movements you can get hold of right upto Valjoux 7750 which would be a tad above your price range on a really good sale.
I don't expect to become a watch collector (I have too many expensive hobbies as it is, and not much money!). I would prefer a watch that is lower maintenance and more durable, which, if I am not mistaken, would mean that a quartz watch would be better?
4) Brand - This is an area which has two camps, there are those who like watches for design, value, technical merits, and those who are biased towards higher end brands (although they will be keen on those aspects as well). How big are you on branding? Do you want ppl to recongnize the brand you are wearing? or would you rather get more value for money on a great looking watch from a relatively lesser known brand. Totally personal preference this one, I fall into the later camp.
As I don't have such a large budget for this, I'd prefer a watch that is technically "better" (e.g., more durable, better features, etc.) over a watch from a prestigious brand that is not as nicely made as some of the more "standard" brands.
5) Other factors - Strap - Metal Stainless steel bracelet? Single deployment clasp? Dual deployment clasp? Leather? Rubber? Alligator? Endless options here, see if you have a preference here.
I'd prefer a metal band, which means I'd need to go with titanium due to my allergy. No real preference on single/double deployment, since I do not know the benefits/drawbacks of them.
I can give you bajillion recommendations for sub 500$ watches, and so can quite a few members here, if you have answers to some of the questions stated above it will help.
Thanks for those questions. It's been helpful in allowing me to further narrow the search, and I hope it will also help you (and others) think of some good suggestions!