Depends on what you want to do with it. I have both the 70-200 and 70-300 you mention but it is the former which gets used the most. In fact I cannot even remember using the 70-300 in recent weeks, but the 70-200 has been extremely busy.
Both are great lenses, and each has advantages and disadvantages over the other, as I say, it really depends on what you want to shoot with them.
Good advise, you have mentioned Lenses that don't really have the same use, between the 70-200 & 70-300 (I have both), the 70-200 is it, buy a 1.4x Converter and you have a pretty remarkable set up, but it's a bit of a Beast to carry about.
If your looking at Portrait/Street Photography then it's the 85f/1.2 II or the 135f/2, again I have both, the 85f/1.2 is simply with out Peer I feel, this is a superb lens, but, the price point between these two lenses is a deciding point for most, the 135f/2 is a great Lens at a ridiculously low price.
Keep in mind also that the 85 does autofocus slower then the 135, but personally I've not found that an issue since going to the 1Dx & 5DMK III, but it was a concern on the 5DMK II & 1DMK IV.