Full of, Characterized by, or Relating to:
* Beautiful: Full of beauty
* Careful: Characterized by care
* Joyful: Full of joy
* Painful: Characterized by pain
* Powerful: Full of power
* Successful: Characterized by success
* Useful: Full of use
* Wonderful: Full of wonder
Making, Capable of, or Relating to:
* Helpful: Capable of helping
* Harmful: Capable of harming
* Meaningful: Full of meaning
* Peaceful: Capable of creating peace
* Playful: Full of play
* Thankful: Expressing gratitude
* Trustful: Capable of trusting
* Wonderful: Capable of inspiring wonder
Other:
* Awful: Extremely unpleasant
* Dutiful: Marked by a sense of duty
* Faithful: True to one's beliefs
* Fruitful: Producing results
* Grateful: Feeling thankful
* Hopeful: Full of hope
* Shameful: Causing shame
* Skillful: Having skill
This is just a small sample. There are many more words ending in "ful" in the English language!