Well, the short answer is
It's you party and you can cry if you want to
as it is your party, you may do anything you want.
If we start with what might be considered to be the most formal and proper invitation
Request the pleasure of the company of
has been used by the White House for formal occasions and the diplomatic corps
since using the third person (not using I or you) is the most formal way to phrase an invitation.
Except for possibly Her Majesty Queen Elizabeth II who actually uses a third person to extend invitations
(source: rozsavage.com)

(source: melbournekitchensandbaths.com)
Less formal occasions and lower level diplomats (Ambassadors, Secretaries of State) might use
>Request the pleasure of **your** company
The pleasure of **your** company is requested
(source: muslimjournal.net)
When one is seeking "the pleasure of *someone's* company" one usually "requests" it.
If one is a mere mortal and it is a party with your friends, one may use
Please join us
You are invited
Hope you can come
In asking for a response to an invitation,
R.S.V.P. (all caps)
RSVP
répondez, s'il vous plaît
is often used and is a formally phrased request by the inviter for a confirmation of attendance. The request is formal since it is using the formal "vous", though people have taken to using "RSVP" as a shorthand without the formal distinction.
The modern non-French non-formal equivalents might be
the favor of a response is requested
the favor of a reply is appreciated
please let us know if you can make it
It's your party, since you're probably not inviting foreign dignitaries or heads of state and it's probably not a once-in-a-lifetime event (wedding), don't get hung up on the wording.
Your invitation is the one year anniversary of your marriage, so you will probably have many chances to word several invitations over the coming years. If your wedding was formal/orthodox, you may want your celebration to be less so.
A fun invitation is a great way to set the mood before the party has even started, just be sure to have a great time!