[Sg1fan]

To sum up, I believe this is what we have, as of August 2008.

Monaco Succession (Legitimate Primogeniture through children and siblings of the current sovereign only.

Prince Albert II, Sovereign Prince of Monaco
Currently no legitimate heirs

Therefore Skipping the following
Alexandre Eric Stéphane Coste (youngest child, illegitimate son of Prince Albert). Albert II could marry his mother and legitimize him but that is highly unlikely.
Jazmin Grace Grimaldi (eldest child and illegitimate daughter of Prince Albert). Due to the circumstances of her birth (her mother was married to another man at the time), marriage to her mother would never legitimize her to ascend the throne.

Official Heirs:
1. HRH Princess Caroline Louise Marguerite, Princess of Hanover, Hereditary Princess (Presumptive) of Monaco (elder sister of Albert II)
2. Andrea Albert Pierre Casiraghi
3. Pierre Rainier Stefano Casiraghi
4. Charlotte Marie Pomeline Casiraghi
5. HRH Princess Alexandra Charlotte Ulrike Maryam Virginia of Hanover
5. HSH Princess Stéphanie Marie Elisabeth of Monaco (youngest sister of Albert II)
6. Louis Robert Paul Ducruet
7. Pauline Grace Maguy Ducruet

Skipping Illegitimate Child of Princess Stephanie
Camille Marie Kelly Gottlieb (youngest child, illegitimate daughter of Princess Stéphanie). The child's last name remains unconfirmed speculation.

Previous heirs to the throne:

Since she is not a child or sibling of the current reigning prince, HSH Princess Antoinette Louise Alberte Suzanne (Baroness de Massy), elder sister of Rainier III (Albert II's father) was removed from the succession upon the accession of her nephew Prince Albert II. Princess Antoinette's children, grandchildren and related progeny were also removed by the same rule.

Succession Scenarios:

Heirs to the throne must be legitimate siblings or children of the current reigning prince.

Should Albert II have legitimate children, they would inherit by Primogeniture (males first, then females in age order). If Prince Albert II's legitimate child inherited the throne, Albert II's sisters Princess Caroline and Princess Stephanie (as well as their children and progeny) would no longer be in line to inherit the throne and only Prince Albert's direct heirs would continue to be eligible.

Should Albert II die without legitimate heirs, Princess Caroline (if alive) would inherit the throne. She could chose (as did their Grandmother Princess Charlotte of Monaco) to decline to ascend and her progeny would inherit by order of primogeniture. Princess Stephanie and her heirs would continue to be heirs to the throne if Princess Caroline ascended and until she died. In that scenario, Princess Stephanie and her proginy would officially lose their place once Princess Caroline passed the throne to her heir through death or by choice.