Eclipse. It's free and very popular.

Download at http://www.eclipse.org

"Code Warrior"...................................

Take a look here: www.javaworld.com/.../jw-tools-ide.html

there are only two worth considering:
IntelliJ IDEA (best of breed, imho): www.intellij.com
Eclipse (almost as good, and free) : www.eclipse.org

your machine may have just enough memory to make the above feasible,
but i'd recommend doubling it to 256Mb at least. don't let your
hardware limit your ide  options; a good IDE will save you far more
time and energy than you could possibly spend on your PC :)

if you want something *really* simple, try:
JCreator LE (free, but quite limited): www.jcreator.com.

however, if you're doing any serious java  coding, you'll be far better
off with one of first two.

IMHO Jbuilder 9 is the best IDE, for me is lighter
than the others in your list. Has useful tools for
develop struts and don't require a lot of memory (my
pc was PIII the first time I used it).
Visual Age has been deprecated for IBM and Sun One,
Netbeans were a little slow to me.
It's a pity that Jbuilder is expenseve.
I heard Eclipse its a very good free IDE.

It would seem that builder.com agrees
with you. I ran across this while looking
for something else:

http://builder.com.com/5100-22-1064560.html

Some recent personal experience on the
matter. I've been using Sun's Forte CE
for quite a while, and today it
suddenly broke. Not sure why, but
rather than try to fix it, I thought
I'd try some newer alternatives.

JDeveloper worked after downloading
the full install. (I tinkered with the
base install for a while before giving
up!) It worked, but it ran slower
than -- as they say -- molasses in
January, and I couldn't get it to
build JAR files in any way that made
sense. It kept wanting to clutter
them up with its own directory structure.

Then I found that Borland has a personal
edition of JBuilder for free. That
went a lot smoother after I figured out
that the help docs were a separate
download. You don't get a lot of stuff
with the personal edition (JavaDoc,
EJB, CORBA, can't remember what all)
but you can do applets and beans, and
since applets are pretty much all I'm
working on right now (and some JSP
another way) it seems like it'll work
for me.

Based on all this, and assuming Sun One
is a lot like Forte was, my vote goes
to JBuilder, too.

A couple other good ones that haven't been mentioned yet are Eclipse
(www.eclipse.org) which is free and Idea (www.intellij.com) which is not free
but
doesn't cost as much money as other IDE's. Personally I think these two IDE's
(along with Websphere which is built on top of Eclipse) are the best on the
market.
Of the two I like Idea better but Eclipse is almost as good.