Speakers suggestion that can be driven hard

If you are blowing tweeters, it's most likely your amp's or source's fault. Either your system is unnecessarily bright or you are getting distortion by over-driving your amp. Most speakers can handle a ton of power but one watt of distortion will ruin them.
What's the rest of your system?

Cerwin Vega D9s

Cerwin Vega CLS-215

As Elevick was stating, it doesn't matter what speakers you have; if you're underpowering them, any speaker will fail. It's very hard to ruin a speaker by over driving it, and quite easy to blow a speaker by underpowering it.

Are you sure your amp is powerful enough?

I have decent equipment Audio Research SP8 and Aragon 4004 mkII. I only have blown the tweeter once. It was an accident. i turned on the system and walked away and the volume was just a bit too high and there was a trumpet part that blasted it. I was too late too the volume control to turn it down. It only sounds like there is damage when I play certain passages of certain songs.