While we're at it, is there anything to hiking up to the summit of Mt. Tam that is better than the hike that dhuey offered?

IOW, if I have a one-shot visit to see Muir Woods, what is the primo hike?

Thanks.

They're different hikes. One's about seeing redwoods and a stream cascading over small waterfalls in deep forest. The other is a peak hike with high meadows, rocky hillsides, and 360 degree views.

Well put. Two very different experiences, despite their close proximity.

Should you find yourself at Muir Woods and want to see a beach, Muir Beach is a quick drive down the highway there (just keep going in the downhill direction). The National Park Service has recently completed a restoration of Redwood Creek just upstream of the beach, including installing a pedestrian bridge across the lagoon and updating the parking lot, so there's a nice (short) walk to the beach. Also, there's a fairly easy (but somewhat steep) trail up to the top of the bluffs there, if you want to get a view out over the ocean, or back over the river valley. FYI, while Muir Woods has standard flush toilets (the sewage is pumped out of the valley over to eastern Marin), Muir Beach has (fairly nice) pit toilets.

As a note, if visiting Muir Woods, you may want to bring an extra bottle of water with you. There's a brass relief model of the Redwood Creek river valley at the entrance. With your extra water bottle, you can simulate rainfall (small storm? big storm?) and the model actually works quite well to visualize flooding and how the lagunal system works downstram.

Big Basin is and will remain my favorite, but if you want something a little closer Portola Redwoods SP is a much more low-key outing than Muir Woods.

Big Basin is also amazing, especially in combination with some beach time nearby.