I'll throw in a dissenting opinion - always the odd guy out. I too have purchased a 75 gallon over Xmas and am done all my supply purchases except for plant and fish. I'm waiting for my son to move out of his room on the 23 of Jan 2010 (he's joining the Canadian (Armed) Forces as a military police officer, then the tank goes into "his" room.
I've been in and out of the hobby three times, this is my fourth time back. As you can imagine, I've owned all kinds of community tanks, big fish, little fish, kinky fish, slithery fish, salamanders, frog, etc. What I am saying is really my own personal philosophy, I'm just throwing it out there to give you yet another alternative.
I now prefer tanks that aren't all "fins." I want a tank set up that is really a relatively "spacious" (as spacious as 75 gallons can be) home for my new residents. I have also found it isn't the fish that get all the attention from visitors. I've owned great looking tanks and the visitors hone in on the large apple snails. Or they love the eel hiding in the substrate. For my 75 gallon this time around, I'm thinking 4 Bolivian rams (yes I have changed my mind about the red line torpedo barbs, they grow to large for my taste in a 75 gallon tank - all fins).
Since these rams will live mostly at the bottom of the aquarium, I'm thinking maybe three to four angels for the mid tank. That's about all I will put in the tank, with maybe a few of the smaller loaches that love to hide (I like surprises when the appear). Oh and I will add some very large snails and shrimp, I know those items will entertain the visitors more than the rams and angles.
I'm in another hobby - model railroading - and (yes I know you're wondering what model railroading has to do with the tropical fish hobby) the latest trend in track planning is - less is more. As you can guess, when a newbie comes into the train hobby, they want track everywhere, with lots of turnouts, etc. But over time, visually and operationally, it has been discovered that less is visually more appetizing than track everywhere.
This is my philosophy with aquariums currently. Yes I can have 75 inches of fish in the tank, but why would I want to; if I keep the stock down to around 35 inches of fish (at full maturity) the tank will be easier to maintain, require less water changes and less risky to leave in the hands of a newbie when I go away to work in Whitehorse Yukon for two months every summer.
The nice thing with small cichlids is they have a big fish personality in little fish clothing (this means lots of entertainment).
Here's a video of two Bolivian rams sparing (not my fish or tank): YouTube - Bolivian Ram males sparring!