Melee, also, has some very powerful weapons available to it and benefits greatly from the right character build. Pyro + the Shish is especially rewarding.
A3-21s Plasma Rifle is probably the best all around weapon in the game, and you could do the entire game with it alone, carrying nothing else, and kick everything's butt with no problems. Maybe you never found it? The gatling laser is a Big Gun, btw and I've played several EW characters very successfully. Perhaps one character wasn't enough for you to make a proper assessment.
I've done a playthrough for both melee and unarmed. Yes Paralyzing Palm was pretty cheap. But overall, I just didn't find either of those to be all that rewarding. The only melee weapon worth anything was the Shiskebob. And Unarmed worked best with the Power Fist. I just didn't like the lack of options, only a few weapons were worth picking up.
I didn't have any problems playing with energy weapons. And yes, I did find the A3-21. I had a energy skill level of 100, and I used the Gauss rifle for most of that playthrough. Sorry, I did a playthrough with the gatling laser and got it confused with energy weapons. But, that was one of my big guns playthroughs.
Personally, I think the weapon options in Fallout 3 were a bit bland. The add-ons brought most of the weapons I used, aside from Lincoln's Repeater.