Very nice. I do like wish granting creatures, especially when they behave differently than one would expect. I think this entry could have been better if some of the genies (hostile genies and the genies that will only offer one item, for example) were grouped together as one of the thirty. There are definitely more interesting genie types that could be added to this entry. I'll add a few under ideas. Good stuff, Cheka.
Horror Genie – This prisoner genie lives in a torture chamber (it's lamp). As it is tortured, it's wish granting power in increased. When the PCs rub the lamp, there's enough 'juice' for one limited wish. The genie will argue with the PCs and try to get them to postpone using their wish so he can enjoy a break from the lamp. If the PCs push for an early use, the genie, might crock them (See #30). Good PCs will not want to use the wish when they realize the consequences for the genie.
Karmic Genie – This three wish genie is similar to #7 in that his wishes have a price and similar to #30 as the price would be considered a drawback. The genie won't tell the PCs about the price but will say things like 'Everything has consequences'. Whatever the PCs wish for has an immediate balancing effect. For example, a fighter who wishes for improved strength will get it at the price of endurance or agility. A wish for a loved one to be resurrected costs the life of a different loved one or alternatively many friends. A wish for an arch rival to be killed will cause another rival to receive a powerful boon or a previously slain enemy will be revived.