I think a good poem really requires a combination of various elements. It may even include a mix of styles. For example, a spoken word poem could include a haiku or a limerick to make it seem more poetic. I think my absolute favorite style would definitely be free verse, however, because it is the most similar to the structure of a song and I like to write songs and listen to songs. I think rhyming is definitely a good element as well, perhaps for the same musical reasons. I like allusions when reading  and/or analyzing poems, but I don't know how easy it would be for me to create one.