The best outdoor post lights

Two facts decide most post-light purchases. The first is power: a hardwired lantern needs a buried cable to the post, while a solar post light needs only sun. The second is the fitter - the collar that sits on the post. A 3 inch fitter is common on round lamp posts; square deck and fence posts take a post cap instead.

Beyond that, a post light is mostly a marker. It does not need to light the whole yard; it needs to show where the drive or gate is and look good doing it. Whole-path lighting is covered in best pathway lights.

Gama Sonic Aspen II - the pick. 250 lumens at a warm 2700K from a cast aluminum solar lantern on a standard 3 inch fitter, IP65, with automatic dusk-to-dawn operation and high and low settings. Real light on a post with no trench and no electrician.
Cons: runs up to one night, so no reserve after cloudy days; 250 lumens is modest; the published dimensions are ambiguous.

Generation Lighting globe post top - the classic wired lantern. A wet-rated white globe for 3 inch posts, ENERGY STAR qualified, which ships with an 800 lumen 3000K LED bulb. The medium socket is rated around 9 watts, so the bulb you swap in has to be a low-wattage LED.
Cons: polycarbonate body with an acrylic diffuser; no photocell, so the automatic part has to come from the bulb; the 9 watt socket rating rules out anything brighter; post sold separately.

Classy Caps Imperial solar post cap - for deck and fence posts. A cast aluminum solar cap for 4x4 posts that lights automatically at night for up to 10 hours, warm or cool by switch.
Cons: 15 lumens is a marker glow, not light to walk by; no weather rating published.

Philips dusk to dawn A19 - the bulb for the wired lantern. 800 lumens at 2700K with CRI 90 listed, suitable for enclosed fixtures, and a built-in sensor that switches the post light on at dark. The full comparison is in best dusk-to-dawn light bulbs.
Cons: damp rated, not wet - the globe's cover must keep the rain off.

Measure the post first. A 3 inch fitter suits most round lamp posts; square wooden posts want a cap made for 4x4.

Give solar a clear sky. A solar post under trees or on the shaded side of the house will not charge well. The trade-off is covered in solar vs plug-in outdoor lighting.

Wired posts are an electrician's job. A buried cable to a post and a circuit connection are not DIY for most people, and not a renter's job at all.

Keep it warm. Both lantern picks can be 2700K. Warm light at the end of the drive looks welcoming and glares less - see 2700K vs 3000K outdoors.