Gee, re-reading my previous response it seems awfully emphatic, sorry! Mondo grass tends to hang on when submersed for awhile, then becomes completely covered in algae, and finally dies off. I just didn't want you to have a bad plant experience the first time.
I think you will find that real plants in your tank will make it even more beautiful, and your fish will exhibit less stress and feel more secure.
The easy ones i mentioned are what i grow, they don't need a lot of light, don't demand a great substrate, and tolerate a wide variety of water conditions. They are also all very interesting species in their own way. A word of caution - don't bury the rhizome (the stem/trunk that all the leaf petioles originate from) of any species that have them, just the roots. And don't be alarmed if new crypts lose all their leaves to "crypt melt" when they are first planted, or when their conditions change too drastically. Just remove the melted leaf material as much as possible, leave the plant alone, and it will grow new leaves suited to it's environment, sometimes appearing quite different.
There are quite a few more plants you could use, look for low light plants at first if your lighting is about 1 watt per gallon. With 2 watts per gallon you can grow the medium light plants. With 3 watts per gallon you can grow all but the most demanding species, but then you are into the realm of fertilizers, CO2 injection, and daily pruning because high light species are mostly very fast growing.