It certainly does depend not only on the program but also on the surgeon. ENT has a huge amount of variety and some people just feel more comfortable with certain areas.
My opinion:
Head and Neck - partial and subtotal gloss with local flap and pec flap recon, total and partial laryngectomies, neck dissections, thyroids, parathyroids, parotids, any skin cancer, maxillectomies, endscopic laser resections of early laryngeal/pharyngeal tumors, mandibular resections that don't require free flaps, and most any other "lump" in the neck
Definitely need a fellowship for free flaps and any sort of anterior skull base resections
Pediatrics - tubes, tonsils, adenoids, trachs, neck masses
Probably need a fellowship for airway reconstruction and maybe for cochlear implants
Otology - tympanoplasties, mastoids
Maybe need a fellowship for stapedectomy, cochlear implants, labrynthectomy
Definitely need a fellowship for acoustic neuroma surgery, encephaloceles, and lateral skull base tumors
Craniofacial - probably need a fellowship for all of it as most ENT residencies don't do any and only a few do enough
Plastics - varies highly depending on where you train; functional rhinoplasty, blepharoplasty, brow lift, face lift, local flap recon of Moh's defects, Botox, laser/chemical resurfacing, dermabrasion, fillers (Restylane, Juvederm, etc.), facial nerve reanimation/rehabilitation surgery, midface and mandibular trauma
You might need a fellowship to do any of these if you train at a program weak in plastics but some programs would have you fully prepared to do all the above.
General - all of the above and endoscopic and open sinus surgery, septoplasty, wide variety of laryngology procedures, sleep apnea surgery
In other words, you would know plenty of procedures well.