The two well-known and distinctive styles of armour in the late 15th century are Italian and German / Gothic.
Italian armour is recognisable for its large, smooth surfaces. It is asymmetrical, designed for cavalry combat, meaning the left arm has maximised protection at the expense of mobility (as it would just be holding the reigns), with large reinforcing plates at the shoulder and elbow, whilst the right arm (weapon arm) is not so heavily protected but has more mobility and articulation. It is usually paired with an 'armet' helmet, which again gives maximum protection but isn't the most practical or comfortable helmet to wear in any non-combat situations. 'Barbute' helmets were also popular in Italy, and would be more of a general-purpose style suitable for more lightly equipped cavalrymen and infantry.
German armour is recognisable for its slimmer, narrow-waisted appearance and heavy use of decorative fluting. It would generally be not as heavy at the shoulders and arms compared to Italian armour, usually using round 'besagews' to protect the armpit, and would be more symmetrical in appearance. Though there are also various styles of German armour that have more of an Italian influence, with less fluting and heavier pauldrons. It is usually seen paired with a long-tailed 'sallet' helmet and a 'bevor' to protect the lower face and throat, a combo which wouldn't offer quite as much protection as the armet, but would be more practical and comfortable – if the bevor is left off and the visor raised, you could walk around in it all day, eat, talk, etc with little hindrance.
English armour – there are some very distinctive English styles of armour which as I understand it have only relatively recently been studied – Tobias Capwell's books are the #1 authority on it, and most of his sources are English tomb effigies which show the armour in remarkable detail, down to every last rivet and strap. There seem to be various different unique forms, but the unifying feature would perhaps be lots of cusped edges and fluting (but different to German-style fluting). It is much more symmetrical in form compared to Italian armour, as it was designed mostly for foot combat. So full mobility of the arms was needed for wielding two-handed weapons, and the backs of the thighs would be more likely to be fully enclosed. Often but not always paired with a sallet and bevor combo.
Now Tobias Capwell's most recent volume was all about European armour in England, and sheds lots of light on 'Italianate' armour popular not just in England but France, Burgundy, etc. The main headline seems to be armour made in Italy for export, or by Italians working in western Europe, adapting traditional Italian styles to English, French and Burgundian tastes. So a little bit more decorative fluting, less asymmetry so better suited for foot combat, but still recognisably Italian in form. He also details some distinctive Flemish (or Italo-Flemish) forms, the most recognisably thing about them being the smooth and unadorned one-piece breastplate (as opposed to two-piece breastplates which were the norm in this era).
If you take a look at the Perry Miniatures plastic box set 'Mounted Men-at-Arms 1450-1500), you will see it has four different armour styles. One German, one Italian, one English and one probably Italianate style worn with a tabard covering it. The German and Italian figures are perfect representations of these two different styles from this period. The English one is very distinctive, but after reading Capwell's book (published some time after these figures were sculpted) I realise that this is not a 'typical' English armour by any means, just one of many different variations. They also mistakenly label it 'English or Flemish', but Capwell's books have taught me that Flemish armour wasn't like this at all, but entirely different.
