I remember seeing the first Operton-based x86 servers from Sun and wondering why they were bothering -- and I remember unboxing the first eval server and being completely impressed with the hardware design. It shouldn't have been too much of a shock -- Andy Bechtolsheim was back in the design seat. I ran a Sun Ultra 40 M2 as my main workstation for several years. It is and was a fantastic workstation. When coupled with a few Sun 24-inch LCD monitors, it would make any geek salivate like one of Pavlov's dogs.
My first look at ZFS blew my mind. To this day, I consider it to be the best file system ever designed. It can and should take over the world -- as long as Oracle doesn't screw it up. Dtrace is another example of "holy wow" engineering from Sun.
I took the Epcot Center-like tour of Sun's Palo Alto showroom, highlighting all things Sun. From the StorageTek SL8500 running at full speed and looking like it could possibly pull a Terminator and take over the world to the SunRay laptop clients, it was terribly impressive. Speaking of SunRay clients, I can recall building a proof-of-concept SunRay implementation back when they required a dedicated VLAN and all the transport was broadcast UDP. Noisy, for sure, but oh so cool.
There are more memories, some cloudier than others. Suffice it to say that I'll miss Sun. I just hope that Oracle understands that it's purchased more than just a company -- it now owns a huge slice of computing history and a significant part of computing's future -- and that it knows enough to not get in the way.