I am planning a trip for this fall or next spring that will include 3-5 days in the Black Forest. I’m interested in getting your feedback on: (a) which sights should a first-time traveler to this area be sure to visit (“don’t-miss” sights); and (b) which sights are overrated and are not worth it (“don’t-bother” sights).

Thanks in advance.

I enjoyed Baden Baden.

The casino there is gorgeous!

Very much enjoyed the walk down Allee Lichtentaler, through the dahlia and rose gardens, down to the end of it, visited a church and Brahams' home. Then took a bus back to town.

And, then of course, there are the baths.

Ahh the baths in Baden Baden - yep, on the good list.

Other places to consider:

Triberg - great place to be smack in the middle of the forest and pretty, not giant, waterfall to hike to.
Titisee - the lake in the southern part of the forest, depends on teh time of year but spectacular scenery in Autumn/Fall
Schloss Hohenzollern - once a castle for the ruling royal family; spectacular views just getting to it, the interior isn't as spectacular but still worth a guided tour.
Offenburg - not so much for the town, but I hear there is a castle (the Ortenberg) which has been converted to a Hostel.

Will you have a car or are you using public transport? Are you into hiking and adventure, or more static sightseeing?

Don't miss/recommended:
Gengenbach
Vogtsbauernhof Museum village
Simonswald valley for postcard Black Forest landscape, I wonder why it is so little known.
Staufen, Münster valley, St Trudpert abbey
The palaces of Rastatt and Favorite (on the northwestern edge in the Rhine plain)
Gernsbach in the Murg valley, a cute little town
Baden-Baden and Freiburg
One of the peaks - Feldberg as the highest, Schauinsland (by cable car from Freiburg), Hornisgrinde, Kandel and Belchen also have nice views
The ruins of Allerheiligen abbey
The landscape around St. Peter and St. Märgen
... and the carnival if you are there at the right time of the year!

Triberg: yes it is touristy, even tourist-trappy, but the two "World's largest cuckoo clocks" are entertaining (now which of them deserves the title?) and walking the waterfalls and feeding the squirrels is also fun.

Don't bother:
Titisee - the village is the worst tourist trap in the whole Black Forest, full of tacky tourist souvenir shops and the kind of restaurants that cater for tour buses. And the lake is nice but not really special.
Freudenstadt, unless you are an expert about protestant church architecture or renaissance town planning. A post-war town, nice but nothing special.

(Hohenzollern is not in the Black Forest but in the Swabian Alb.)

<(Hohenzollern is not in the Black Forest but in the Swabian Alb.)> Ja, ja ok, technically not in the Black Forest, but so close it's worth a visit, esp if with car.

Titisee in Autumn/Fall is pretty, and the tourist tack can always be skipped in favour of scenery.

My don't-bothers are Triberg, Titisee, and Freudenstadt, for reasons already mentioned.

By far the best experience I had in the Black Forest was visiting Allerheiligen and hiking to the nearby waterfall. There is something about a ruined church in the middle of the forest that is very special. Best viewed in dreary, foggy weather to add to the atmosphere.

Hohenzollern is definitely not in the Black Forest, but since it was mentioned, I'll add that it is one of my favorite castles in Germany (this coming from a castle fanatic) and is well worth a visit.