My thoughts after binge-watching all 5 seasons
In no particular order - and, of course, with spoilers:
According to the very first episode, the aliens destroyed every major city. Either Washington DC wasn't on that list or their bombs weren't all that impressive.
First the Espheni wouldn't tell why they came, then they said there was a huge threat coming and humans weren't ready to face it alone, then they said it was all because a bunch of Peruvians armed with spears killed an alien princess 1,500 years ago. *facepalm*
Yes, the spear-wielding Ethiopians managed to fight off Italians with machine guns back in 1896, but a space-traveling race of aliens?.. Ridiculous.
Ben should have been died with the rest of the Espheni because of his spikes.
Did they get a new writer/director/producer in season 4? The whole "Skitler Youth" thing, combined with the rapidly aging girl (not at all stolen from "V") came out of nowhere.
Anthony was the male version of a stereotypical damsel in distress. If anybody ever decides to re-watch the entire show, could you count how many times he got knocked out, wounded or taken prisoner? The guy should have had permanent brain damage by the end of the series.
I loved the first season's finale when they actually had to conserve their bullets. Where did all that infinite ammo come from in season 5?..
For that matter, where did they find all those guns after they escaped the ghetto in season 4 with nothing but a bunch of sticks and stones? (It was a big deal when they found that old hunting rifle in a barn.) Was the Chinatown secretly an arms-trading hub? Because that's the only explanation I can think of.
Maggie and Isabella should have hooked up. The whole uber-possessive thing with Ben and Hal basically fighting over who will own Maggie was painful to watch. (Contrast that with one of the very first episodes of "Lost World," where the jungle-grown heroine tells the bookish character and the local tribesman that neither of them owns her.)
Help me with the math here: we were told that Charleston had around 2,000-3,000 people. Second Mass had about 200 by the time they got there. After the unpleasantness in season 3, they somehow ended up with just a hundred or so people? I find it hard to believe that the building collapse caused by the explosion managed to kill over 2,000 people while the entire main cast survived without a scratch.
They spent at least 3 months in the ghetto and never once noticed that the giant spaceship had a cable running to a big obelisk thingy right outside the fence?
The Volm never once noticed the power generator on the moon? And did the Espheni freeze the moon in place? Because otherwise they'd get just a few days of energy transmission per month because, you know, the moon kind of tends to rotate.
Why would the Espheni keep building all of their important doomsday devices in North America if they knew there was so much armed resistance? Go build it in Outer Mongolia or smack in the middle of Australia, and call it a day.
Did no one bother to find Pope's corpse after the explosion? Assuming he recovered someplace else later (I don't feel like watching the ridiculous scene again), what exactly was his cause of death in the finale? Aside from having a really bad case of the uglies, there was nothing wrong with him if he survived the explosion and recovered enough to walk to Tom Mason's rendezvous spot with the alien tentacle monster.
It's super-convenient that all the aliens (Espheni, skitters, Volm, etc) could breathe oxygen.
So Earth is the only inhabitable planet in this galaxy, eh? I guess they were using an astronomy textbook from the 1950s as their main source of information...
The skitter spaceship they flew to the moon was controlled by a bunch of cables that were about waist-high. How exactly were the 10-foot-tall overlords supposed to use them, again?
Whyyyy exactly couldn't the Volm carpet-bomb Washington DC with their space ship? I know Cochise said "it would not be possible" but fine - why couldn't one of the militias liberate a nuclear warhead and fly it in?
-------------------
I really, really hoped season 5 would be much better. The first couple of episodes were pretty great! And then it just self-destructed. I never thought I'd hate another sci-fi finale as much as I hate BSG's. (BSG spoiler: hey, let's just blindly teleport to the coordinates this creepy little girl gave us, and then throw away all of our technology, and then go impregnate some cavemen who just happen to be genetically compatible with us, and then probably die within 5-10 years because we've thrown away all our weapons and medical supplies. Makes perfect sense!)
The first season was great... This is one of those times when I wonder if life could be easier if I were a lot dumber. After all, shows like "Scorpion" (where they race around at 220mph in a convertible to upload a program onto a plane because there are no backup airports in Los Angeles) are apparently popular enough to get 3 seasons, whereas Firefly (peace be upon it) never even got a full season. Ugh...
[/rant]