I think they are hard to compare. It's like apples and oranges they are both fruit but still completly different. Different ideas, concepts, and even age groups. I like them both, but for two completly different reasons.
The Host interests me because the protagonist is a strong female character who has struggles with herself. A guy isn't involved in the story until later in the plot. The story is about identity and who Wanderer is as a soul. Within her identity includes a question of who she loves, therefore causing guys (Jared, Jamie, and Ian) to be involved.
Twilight interests me because the protagonist is a girl who meets someone she could potentially spend the rest of her life with, but she encounters issues involving that which shapes the plot. The story is basically about Bella wanting to be with Edward, and deals with issues interfering her desire to be with him and love him forever.
Therefore both stories are different and includes its own conflicts. I enjoy them both. However since I am a hopeless romantic, I love Twilight. And since I encourage stories involving discovering one's identity, I love The Host.