I'll hop the necromancing bandwagon and bring this one back, too.
We have a friend visiting and, of course, are doing a crapload of sightseeing. I'm so glad I did my homework online, reading not only websites for each attraction but also plenty, PLENTY of tourist reviews. I hadn't even thought to come here and search it up, but I did immediately after we got back yesterday to see if anybody pointed out what we had figured out ourselves.
Tokyo Tower is a wonderful place to go to. I thoroughly enjoyed the wax museum and rock shop near the end, and I would have loved to go to the Guinness museum and aquarium...but the observatories seem like HUGE tourist traps. Why pay ¥2100 per person to get a semi-quality view? Seeing it from "the other side", after a revelation of sorts, it seems like many tourists only go because they feel obligated to see something that they "should" see.
However, the
Tokyo Metropolitan Government Building that Maggie has mentioned is UNBELIEVABLE. Not only does it offer a HIGHER view than Tokyo Tower, it is 100% free! There are two towers, the North tower and the South tower, and the South tower is considered to have a "slightly more interesting" view than the North, but the North is still breathtaking...not to mention, the South tower closes early at 5pm, and we were at the North in the vicinity of about 7:30pm. They have express elevators specially designed to take tourists straight to the 45th floor, complete with uniformed escorts. Be warned that any bags you carry are subject to inspection, but the escorts are gloved, they are NOT intrusive (they asked me to unzip my purse and glanced inside, did not poke around at all, then bowed very gratefully for the cooperation) and they are very polite. Also on the 45th floor are plenty of souvenir kiosks and a very cute but very small and private Italian restaurant.
To get to this building, simply hop the train to Shinjuku station but DO NOT LEAVE the station. Winding tunnels they may be (and the walk feels worse than Narita!), but if you follow the signs underground, it will take you RIGHT inside the lobby of the TMGO.
Considering we went not only to Tokyo Tower but were heading to Hard Rock Cafe regardless, Shinjuku was on the way home anyways and it was so worth it. So in my opinion, when it comes to observatories, TMGO > Tokyo Tower BY FAR.
(Please excuse the amateur photography...)

Tokyo Metropolitan Gov't Office. Impossible to miss!

Example of one of the many views available