What is the best mens watch under $100?

Citizen Men's BM8180-03E Eco-Drive Canvas Strap Watch

You will never run late with this men's sporty, Eco-Drive timepiece. From the stainless steel case, green canvas strap and 12/24 hour time indicator, the bold details never end. Additional features include a day/date indicator and water resistance... read more...

This is a cool military style watch that I recommend. I used to have one, and unfortunately I broke it, through no fault of the watch.
I love this style in that it is quite casual, but can be worn to fancier occasions without looking odd or out of place.
It's very well crafted and has a durable strap. It's got some weight to it and it feels nice and solid on my wrist.
Time and date was alway accurate.
I need another one!

✔ Highest voted answer

Reply · Send thanks · posted 232 days ago · 10 people agree

Skagen Men's 233LTMN Titanium Black Mesh Watch

Cap off your wardrobe with the clean lines and sleek European styling of the Skagen 233LTMN. The thin and ultra light black tone titanium case frames a striking blue dial with silvertone hands and stick indicators. A black tone titanium plated sta... read more...

This should be the picture in the dictionary for the word 'sleek'.
The sleekest of all the watches I've ever seen! Very very thin and so attractive. I like the blue face, but there are other colors available.

Reply · Send thanks · posted 232 days ago · 8 people agree

Casio Men's AQ164W-7AV Ana-Digi Sport Watch

Casio's Ana-Digi sport watch is the ideal watch for men on the move. It features a full-face digital and analog display over a white dial for time telling at a glance and a black resin band for all-day comfort. Great for swimmers and runners, this... read more...

For sports wear or just for durability.

Reply · Send thanks · posted 230 days ago · 1 person agrees

Skagen Men's 433LSL1 Slim Brown Leather Watch

Texture and a touch of style. Genuine leather straps in brown connect to a round stainless steel case. The layered silver white dial features indicators and hands in chrome with a small eye second hand. read more...

Skagen makes a great watch in this price range.
I'm a leather band kind of guy, mostly for comfort reasons.

Reply · Send thanks · posted 232 days ago · 1 person agrees

Invicta Men's 6620 II Collection Chronograph Stainless Steel Silver Dial Watch

With its polished stainless case and durable flame-fusion crystal, the Invicta Men's II Collection Chronograph projects an air of authority and confidence. The watch's unidirectional hatched bezel features engraved numbers in five-minute increment... read more...

This is a beautiful Invicta. My kind of watch right here! I like the way these look and function. I have owned a few in my day. Whenever I am in the market for a new watch, I can't make myself buy a different brand because I am too happy with these!
They are very stylish silver and durable.
This one is medium sized, although slightly larger than I thought after seeing the picture.
It works as good as it looks.