The more recent Holmes' will have the advantage of being more top of mind. I think there is a spectrum from very traditional to very modified Holmes'. Alright, they're all modified to some degree. For my money, Clive Merrison invokes the near perfect Holmes with the distinct disadvantage of being only audio. But I encourage anyone, who hasn't heard his radio plays, to do themselves a big favour and have a listen. It's such a pity that he didn't appear as a visual Holmes because, I also believe, he is by far the closest looking Holmes to the original Sidney Paget illustrations... if that's important. See wallofclebrities.com.
I also really enjoy Jeremy Brett's Holmes, but, I had to get used to the campy theatrics. I don't mean to be disrespectful to such a superb actor.
I'm not necessarily a traditionalist Holmes fan either. I loved the clever, dynamic, "all over the shop" of Benedict Cumberbatch and Robert Downey Jr's modernisations. The dramatisations just keep getting better and better. I think that's a natural evolution.
At the end of the day, my top 5 Holmes' are interchangeable, but I do like Clive Merrison. For the record, I also liked Richard Roxburgh's 2002 Holmes as well, despite the obvious criticisms of the story line and being a "blonde" Holmes. It's very watchable.
That's my penny's worth.