In a letter to John James Ruskin on 15 June 1845 ( in Shapiro, Ruskin in Italy: Letters to his paren ts 1845, p. 114, Ruskin writes that 'the Elgins' (i.e. the Friezes of the Parthenon removed from the Parthenon in Athens by the agents of Lord Elgin) had spoiled him for all sculpture except that of Michelangelo. In another letter of 10 July 1845 (in Shapiro, Ruskin in Italy: Letters to his parents 1845, p. 145, and at Works, 4.xxxiv) Ruskin puts Michelangelo at the head of the class of those who demonstrated 'General Perception of Nature human & divine, accompanied by more or less religious feeling. The School of the Great Men. The School of Intellect.' Others in descending rank order were Giotto, Orcagna, Benozzo [Gozzoli], Leonardo da Vinci, Ghirlandaio, and Masaccio.
The writing of Reynolds on Raphael raises the question of the relative merits of Michelangelo and Raphael, and in Modern Painters I Ruskin's assumption is that Michelangelo is to be ranked with the greatest artists in every field.
For Ruskin as for Reynolds, Giovanni Bellini was one of those whose work marked the end of the old style, but for Ruskin in 1871 on the relationship between Michelangelo and Tintoretto the change was for the worse, and the 'fatal motto' for the future of art was 'Il disegno di Michael Agnolo' Works, 22.83. There Ruskin addressed the issue of 'disegno' - the intellectual grasp of ideal form - as it was raised in Vasari on Michelangelo, and directly contradicts not the substance, but the value judgements of Reynolds's account of Michelangelo
However it is much less clear where Ruskin stands on these issues in Modern Painters I. At MP I:xxx in his discussion of the flowers of the foreground of Titian 's Bacchus and Ariadne what Ruskin says about Titian seizing 'the type of all' seems closer to the ideas suggested by Reynolds, by Vasari, and by Michelangelo himself than it does to Ruskin's own later views.
See Ruskin and the Italian School.