Depends on his lifestyle and his passion for watches. If he is an outdoor rough guy, you will be prioritizing durability. If he is an office dude, you can sacrifice it for better looks.

The most important tip to begin with is: if the watch brand also makes underwear, it’s not a decent watch brand. You can discard Armani’s, Boss, Dolce Gabanna etc.

The default recommendation is a watch on a steel bracelet, 100m water resistance and sapphire glass, all for durability purposes. Be aware that the gold will be plated or PVD at best and will scratch away with wear.

If he is a watch guy, mechanical movement might be something to consider, but if he does not care about watches, solar or quartz will be better for him.

The most important part of a watch is the sizing, you need to get his sizing correct. Please visit with him a jewelrer. If you dont want to, the way to go is 38-41mm, you can’t go wrong. If he is a bulky strong guy, 40-42 is good, if he is thin 36-38 will be better.

You could consider Tissot PRX quartz, Citizen Tsuyosa, Seiko Presage and Orient for example