Love marriage is not ok in Islam. But is not Muhammad's (Peace and blessing be upon him) first marriage was a love marriage? Bibi Khadijah (May Allah be pleased with her) saw him, liked him and proposed to him indirectly. Will you discuss it? So far I know Hazrat Musa (Peace and blessing be upon him) also loved a girl and married her.

Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
All the books written about the biography of the Prophet Muhammad (Peace and blessing be upon him) confirm that Khadijah () herself showed interest in marrying the Prophet Muhammad (Peace and blessing be upon him) after knowing his noble characters and good conduct. This act proves her good understanding, wisdom and superiority.
As for the love of Musa () to the girl whom he married. Allah Himself made it clear that the girl's father married his daughter to Prophet Musa. Allah Reports this story in Qur'an by Saying: "And said one of them (the two women): "O my father! Hire him! Verily, the best of men for you to hire is the strong, the trustworthy." He said: "I intend to wed one of these two daughters of mine to you, on condition that you serve me for eight years, ……."[28:26-27].
There is nothing in Shariah that make the stories mentioned above contradictory. However, the marriage based upon love does not contradict Shariah if there is no violation of Islamic rules. Sometimes Allah put in the heart of somebody the love of someone but that person does not commit any sin nor violates any rule of Shariah, i.e. he does not touch her and does not even stay with her in seclusion. However, he asks her guardians to accept marrying her to him legally.
On the other hand what is forbidden is having love relationships before having completed the marriage contract as practiced nowadays. Today relations between a man and a woman contain many forbidden acts such as staying alone with her, looking at her beauties, and other illicit physical contact, etc.
Allah knows best.