Best greetings to anyone - it is a wish of health and happiness, expressed genuinely and sincerely. In the text of the message should sound sincere respect for the birthday boy, recognizing his abilities, skills, talents, the joy of meeting with this person.
You we appreciate, respect,

You are sure always

And happy birthday to congratulating,

We wish you happiness for years to come.
Now greetings are almost white magic, conspiracy, health, happiness and longevity.
Young people love humorous and light, congratulations. In such cases, you can do literally one line. For example, "Successes and gingerbread. Or, "Let thy life is peace."
Live, not knowing the sorrows and troubles,

And strong will let health

For many, many, many years.
If the birthday boy loves greetings in verse, and with imagination the trouble, you can use ready verses. You can refer to the verses of the classics, you can open one of the greetings, only to redo some lines.