By old I assume you mean bands in their 60s and older. I had the same positive experience with Daltrey and Townshend a few years back. I expected Roger's voice to be a weak spot but he was surprisingly good that night. The backing band was Simon Townshend and Ringo's son Zach Starkey was fantastic. Was able to knock the top artist off my bucket list last year when I saw Clapton at The Garden. He sounded fantastic but he's been playing a fairly static setlist the past 4 years or so. Was so happy to see him but for $230 for a 200 level seat, I wouldn't do it again unless he changes up his setlist. Here's my list of other older artists I've seen the past 5 years.
Steely Dan-No Becker anymore but still a great show. Fagan stayed within his vocal range, great overall musicianship
Petty and Heartbreakers-Fortunate to see them before Tom passed, especially in their home state of Florida. Mike Campbell is one of my favorite guitar players, hope he stays active.
Dead and Company-With Mayer I've seen them three times, he and Oteil Burbridge have really energized the band, I highly recommend them. Mayer has really stepped into the Jerry role and been a perfect fit.
Van Halen-Eddie is clean and playing great. If Dave stays within his now limited range they're good to see, especially since ticket prices are pretty reasonable.
Pearl Jam-Current top bucket list band, excited to be seeing them Labor Day Weekend at Fenway