Our new friend Mr. Happy is also expressing the opinion that Ramana never enlightened anyone, except perhaps his mother and Lakshmi the cow. This is apparently based on the fact that Ramana never seemed to explicitly acknowledge the enlightenment of any of his devotees. But this relies on a serious misunderstanding of how Ramana operated. Ramana simply wasn't in the habit of making official statements about anything, including himself. For example, he almost never acknowledged himself as a Guru, despite everyone relating to him that way. He never even gave anyone formal diksha (initiation) which is the traditional rite of receiving the Guru's blessing and establishing a formal relation to him. He didn't adopt the formalities of being a Guru, by Indian standards at least. He considered himself "Atiashrami", meaning "outside the formal rules of spiritual life". He didn't adopt any titles, any distinctions, any official roles, any official relations, and he didn't acknowledge them in others. He didn't consider realization to be some kind of official "position" that depended on any outside authority's acknowledgement, from others or from himself.
On the other hand, Ramana certainly did seem to make informal acknowledgements of the realization of some devotees. In one famous incident recounted by David Godman in his book on Lakshama Swami, "No-mind, I am the Self", the 23-year old Lakshmana sat down for meditation with Ramana for the first (he'd seen him a few months before during a celebration at the ashram) and within a few minutes was drawn into deep and spontaneous self-enquiry, which he'd never practiced before, and within a short time realized the Self. He sat virtually motionless before Ramana for the next six hours, and finally wrote a short note which was passed to Ramana, which said "By your Grace I have realized the Self in your Presence today". The attendent said he'd never seen such a note before, and when Ramana received it he looked directly at Lakshmana and beamed with incredible joy, a look the attendent said he'd rarely seen before, but which always seemed to indicate full blessing and acknowledgement. Is that a "formal" acknowledgement of realization? Of course not. Ramana just wasn't into that sort of thing. But everything about his relationship with Ramana after that indicates that he took Lakshmana's confession seriously.
Likewise with long term close devotees who came to him and spent time around him. But there were also people who merely came to ashram and quietly realized, such as the famous Bhakta Ram Das who spent about a month at Ramanashram and said that is where he realized. We don't know how many others came and realized without it being made known. The best estimate I know of Ramana's known enlightened devotees would include but not be limited to this list:
Sri Muruganar (See Padamalai)
Annamalai Swami (See Living By the Words of Bhagavan, by Godman also)
Poonja Swami (Papaji, many books available, esp. Nothing Ever Happened biography)
Lakshmana Swami (see No-Mind, I am the Self, bio by Godman)
Mastan (a muslim devotee)
Swami Ram Das
Lakshmi the cow
The list could be added to I'm sure. The point is that Ramana definitely did produce living realizers who could be seen and verified by others. Certainly many have seen and verified for themselves the realizations of Poonja Swami, Annamali Swami, Muruganar, and Ram Das. Whether they have official "certificates" or realization or not from Ramana is hardly material. The evidence of their realization is much stronger than, say, the evidence for Ramana's mother or for Lakshmi, both of whom Ramana did give formal acknowledgement to.
The point is that Ramana's teaching and Presence worked. It produced good fruit, from helping beginners get on the path to helping advanced devotees realize. The same can't be said of Adi Da's teaching work. Adi Da says that his work is superior to Ramana's, but the evidence says otherwise. I believe a couple of years ago Adi Da was taking questions from his devotees, and one of them asked about his missionary service to Da. In the course of answering, Adi Da said that at a certain point one has to be judged on results. He said that if this devotee gave presentations about Da for years and years without any positive results, he would have to question his own qualifications for the work. If we were to apply that same criteria to Da himself, we would have to likewise question his own qualifications as a teacher. He has been teaching for over 35 years, and has no serious results to show for it, even by his own admission. As he himself says, all his devotees, even those who have been with him from the start, are just beginners without any real spiritual maturity. At a certain point you have to look at that evidence and stop blaming the devotees, and see their lack of progress as a reflection of the teacher himself.
Some teachers just aren't very good at their job, regardless of their credentials. I recall reading Papaji saying that J. Krishnamurti may have been enlightened, but he had no capacity to teach or communicate it to others. And who knows, maybe Da actually is enlightened, let's at least entertain the possibility, but though it appears that he has an ability to communicate yogic experience of the Divine, he doesn't appear to have the capacity to make it actually "stick" and grow the devotee. The reasons for that aren't too hard to see, if one examines Da closely. Ramana apparently did have the capacity to guide devotees along quietly through real growth all the way to full realization. Not every teacher can do that, apparently. Da seems to be one of those who simply can't do the trick, or we would see some kind of evidence of at least serious spiritual growth after 35 years. People do get some genuine spiritual experience, and they do learn things along the way, but profound spiritual results are seriously lacking. One has to begin to question the qualifications of the teacher at some point, and I think that point was reached quite a long while ago.