hmmm...I can see it on my comp

ok

The Deadly Mantis

scratch that...it wasn't eco....after doing a bit of research I found out it was more of geological events that released a giant, prehistoric Praying Mantis from the Arctic ice

Most of the good ones involve insects.

I remember watching The Swarm and Prophecy at about the same time and liking them both. Especially Prophecy.

The Host was a recent one...

The very beginning is based on a real case.

the end too .....it's all real.

Hahaha, I'm serious...

"Albert McFarland, 57, was charged with violating a water-quality law for
ordering two morgue employees in February 2000 to pour out about 192
bottles containing 16 ounces each of the embalming chemical. The fluid
eventually flowed through sewage treatment systems into the Han River,
the main source of drinking water for Seoul's 12 million people."

The really obvious ones have been mentioned... How about:

• Black Sheep
• Isolation
• Frogs
• Return of the Living Dead
• C.H.U.D.
• Mimic
• Larva
• Bats
• Severed: Forest of the Dead
• Cabin Fever
• Hills Have Eyes (to some extent)
• Jacob's Ladder (human atrocity/experiments against nature)
• Attack of the Giant Leeches
• Attack of the Killer Shrews
• Them!
• The Incredible Shrinking Man

As people mentioned, pretty much any Roger Corman or 50s-60s Giant Monster flick.

My favorite. Hedorah scared the crap out of me the first time I saw it when I was six.

One of my fave Godzilla flicks, definitely.

Ha! That's my buddy Tim's film!