What size tank and what other fish are in it?
With gouramies it can often be tricky to decide on good tankmates because each individual has a significantly different character and their temperament and prefferences vary greatly.
The first thing you need to know is that three-spot gouramies (trichogaster trichopterus) come in many color forms - included in these are the golden, blue (natural) and opaline. So the fish you want to add is actualy the same species as your original fish.
Three-spots are, in my opinion, the most aggressive of the common gouramies and you shouldn't ever keep 2 males together in anything but a very large tank with lots and lots of cover. Even a male with a female can result in the male bullying the female to death.
Some people have said that the different olor variants don't bother each other but I have to disagree. All the three-spots I have kept have acted the same towards any other three-spot, regardless of color.
Do you know the sex of your current fish? What about the fish that died? Males have a pointed dorsal and females are deeper-bodied when full of eggs. If both your fish were male, you can consider adding a female or, if you have space, better still would be 2 females to divide the male's attentions. If your old fish had been female (the one that was killed), you are better off avoiding any more gouramies as your current fish will probably kill any others you try to add.
I doubt your current fish is female if she killed the other gourami - females are generally peaceful.
Deffinately avoid adding another male.
Remember that gouramies, especialy males, are very territorial. Re-arange your tank before adding the new fish and watch carefuly for any disputes. They should settle down soon if your current fish decides to accept them and leaves them to establish their own territory.
