I've seen it before, the name's on the tip of my tongue, but I can't remember it. A highschool student finds a helmet from an alien bounty hunter/police officer/something like that and he puts it on to get special powers he uses to hunt other aliens, anyone know what it's called ?

I wonder if your memory loss has anything to do with the 7 am shots of everclear you take every morning? :D

That's a lie ! I only take 5 !

Ben 10 ? :P

No...

There's nothing that specifically comes to mind, there's Gantz where dead people fight which might have something to do with aliens. Project Arms where kids have alien crap implanted in them and fight.
Or Bio Booster Armor Guyver, where they find some kind of morphing armor and fight weird experimental creatures.
But none of those are precisely what you described.
Any idea if it was a movie or a series?

Yes ! That's it !



http://en.wikipedia.org/wiki/Sadamitsu_the_Destroyer

Well that was indeed quite different from the original description.

No, that's pretty much it .

Delinquent gang leader, robot instead of alien bounty hunter, team up instead of wearable equipment.
You're right, that is indeed 100% the same my bad.

Yes, but I stand by the point that it is quite different from the original description.
It's good that he got it and I've added it to my 'look into it' list of anime.