If you don't want to spend more than $100 for a very substantial automatic men's watch, you should consider the Fossil line, which are homages to more expensive brethren like Emporio Armani. 

(In fact, Fossil Watches is a design and distributor of many name brand watches, among them the Armani and Hilfiger lines.  Fossil's marketing strategy is to fill the "higher-end" department stores, like Macy's, and to stay away from JCPenney's and Sears.)

OK, I shop in mall department stores and not on Rodeo Drive or 5th Avenue, and drive a Nissan, but that doesn't mean that I don't like a nice dress watch.  The Fossil Gunmetal Ion ME1005, if you can get it, is such a watch.  I lucked out one day and got it for under $60 at a Macy's department store sale. 

It's flat metallic case and bank is not sprayed-on chintz, but buffed blended metal that evokes titanium.  The face design is well thought-out, hour markers are bold, and the gold doesn't look like it will tarnish green under sweaty conditions.  I've worn this particular model when I go travelling and have had several stewardesses comment on it.  When I went to Eastern Europe, my Fossil drew attentive looks from young, aspiring execs who rode the subway, and a German tourist.  Plus, if you get any Fossil watch with a leather band, it will remind you of a soft Italian leather shoe that feels like a old, comfortable friend.  Execution in the fine details definitely makes Fossil automatics worth having in your watch collection.

Moreover, I read watch forum articles that link Fossil watches with Seagull Tianjin watch movements, which are the most reliable movements from China.  Seagull has made appearances at Swiss watch fairs, won a Swiss patent on a new movement design (this is big).   Anectodally, I've tested my Fossil watch against my cell phone and it seems to be dead-on at the end of the day, so it speaks to the quality of its watch movement.  Also, Fossil has acquired some Swiss watch movement manufacturers, so there is some speculation that the higher-end watches (probably above the $200 price range) could benefit from this. 

Update Jan 2009:

Found out from reading several sites that the Fossil "TWIST" line is not a true automatic.  It's a battery operated watch, with the look of an automatic.  Don't know if the automatic spring in the front really does anything -- but I doubt it.  One site said the spring drive was just for looks; and even my Seiko Kinetic, which uses a combo battery / automatic movement technology stops after several days of non-use.  The Twist line, on the other hand, keeps time like a regular quartz watch.