Below is a list of some trojans.
Back Construction - Not as many features as some other trojans. Allows someone to upload/download files to/from your computer. Also allows someone to view your cached passwords.
Backdoor - Many options. Not as common as some other trojans.
Back Orifice - One of the first (and a somewhat lame) trojan horse written by a hacker group called Cult of the Dead Cow. This hacker group has been around since the 80's, and they were sued for writing BO. They claimed BO was meant as a remote administration tool and they can't help it if someone abuses it. If that's so, then why did they design BO so it runs discreetly in the background? Why didn't they design it so it display as icon on the taskbar to alert the user that the comptuer is being accessed remotely?
BO2K - A newer version of the above with many more options.
DeepThroat - A common and powerful trojan horse. Similar in capability to Sub 7.
Doly Trojan - There are many versions of this one. It seems fairly powerful and gives the script kiddie almost complete control of your computer.
Donald Dick - A fairly powerful trojan written by a Russian programmer. This one is rare, so some anti-virus programs don't detect it.
Gate Crasher - Written in Visual Basic. Not impressive.
Girlfriend - Like so many of the hacking tools on the internet, this one comes from Russia. The server is called Girlfriend, and the client is called Boyfriend.
Hack 'a' tack - This trojan is distributed as shareware. The script kiddie has to register it to get the fully functional version (LOL).
Illussion Mailer - This trojan doesn't allow the script kiddie to do anything except send email thru your computer. This is useful because he can be 100% anonymous when sending emails. He can mail bomb someone thru your computer and get you in trouble.
Netbus - One of the first trojan horses.
Netbus Pro - An improved version of the above with many more features
Prosiak - Not bad, written by a Polish programmer. Allows script kiddie to connect to you thru a proxy so you can't get his real ip.
Psyber Streaming - This trojan doesn't allow the script kiddie to do anything except receive streaming audio from your computer.
Shit Heep - This trojan does not allow script kiddies to cause any damage to your computer. They can only cause annoyances such as opening/closing your cd drive, hiding your mouse/taskbar, activating your screen saver, etc. The only thing this trojan can do that could be considered dangerous, is it can force your computer to restart.
Sub Seven - One of the most common trojan horses with many features, including remote ip scanning and access to your webcam.
Telecommando - Don't know anything about this one. Not that common.
The Thing - Although this one does not have many options, it's server size is extremely small (8kb) which makes it very easy to hide.
Y3K Rat - As many options as Sub 7, but not as common. This one is fairly new, so some anti-viral programs won't detect it.
I have not personally tried out most trojans, so I do not know much about various trojans' capabilities. If someone could email me and give me a url where I could find detailed descriptions of various trojan horses, it would be much appreciated.