SEIKO male watches Essentials SS Automatic Green Dial

Why it's worth it

This is a real automatic watch — no battery, a see-through case back, and a green dial that shifts with the light. It's the gift you buy for one person, usually your brother or the best man, rather than for the whole party.

It runs on movement, not a battery. He wears it, it winds itself; it sits in a drawer for a few days and he'll be resetting the time. Seiko lists a 41-hour power reserve, so it keeps running through a weekend of steady wear. That small ritual is a lot of what makes a mechanical watch feel personal instead of just useful.

Nothing else on this list says thank you as loudly. The screw-down case back is see-through, so the movement is visible — an unusual touch on an everyday watch. The Hardlex crystal shrugs off the scratches a daily watch collects. And the green dial works with a suit at the ceremony and with a t-shirt six months later, which is the range you want.

From our review of 8 groomsmen gifts

What we like

• +It runs on movement, not a battery
• +Nothing else on this list says thank you as loudly
• +Owners are consistent about one thing: the green is far darker in person than the photos suggest
• +Plan a quick trip to a jeweler

What to know

• –The see-through case back is the nicest thing about it and it rules out engraving, which makes this the least personalizable…
• –Buy carefully. At least one owner reported that Seiko declined warranty service because the seller wasn't an authorized dealer,…