Some earlier works by Dead-Or-Alive - You Spin Me Round can also be referred to as Hi-NRG and also as just Eurobeat, and that song was released back in 1984! However, the majority of that sound was during the late 80's. Since there are so many genres I did not include which were not influenced by the Italians, I only decided to list those which Italians actually helped to pioneer or directly related to them in one way or another.
I made a short list of what I would classify as what:
DISCO = 70's, many songs produced with real instruments. Examples: The Supremes - I will Survive
HI-NRG DISCO = late 70's, early to mid 80's, most songs produced with only synths OR synth + real instruments, the first introduction to the "galloping" baseline.
Examples: Donna Summers - I Feel Love, Patrick Cowley - Menergy
ITALO-DISCO = technically, started in the late 70's, not really known officialy as Italo-disco until early to mid 80's, during it's peak-point. completely synthesized. Earlier works incorporated elements of new wave. Usually slower baselines when compared to Hi-NRG Disco. Focused more on melody and baselines than strong vocal work.
Examples: Ken Laszlo - Hey Hey Guy, Den Harrow - Don't Break My Heart, Valerie Dole - Get Closer
DISCO POP/DISCO FUNK = anywhere from early 80's to mid 80's. disco beats made with synths, sometimes real instruments can be included as well, focused more on vocal work than synth work.
Examples: Chaka Khan - Fate, North End - Tee's Happy, Madonna - Holiday, The Whisperers - The Beat Goes On
Hi-NRG POP = mid 80's to late 80's, more popish than Italo-disco, sometimes not as hard baselines or synths compared to Italo-disco. more energetic than DISCO POP/DISCO FUNK. Used a lot during aerobic exercising during the 80's. Focused more on vocal work than synth work. Examples: Irene Cara - What A Feeling, Samantha Gilles - Don't Let Go, Bonnie Tyler - I Need A Hero
Hi-NRG EUROBEAT, AKA Hi-NRG ITALO-DISCO = Hi-NRG DISCO galloping baselines + clapping sound effects.
Examples: Dead-Or-Alive - You Spin Me Round, Michael Davidson - Turn It Up, FCF - Bad Desire, Atrium - Midnight Dancer
FREESTYLE (sometimes known as just FUNK in some parts of the world) = mostly in the 80's, some productions in the 90's as well. A mix of house, italo-disco, and HI-NRG, and Latin sounds. Examples: Shannon - Let The Music Play, Noel - The Question, Donna Williams - True Love Never Dies
EUROBEAT = clapping sound effects put on higher speed so they are not as noticeable and may sometimes be completely absent. Some songs may sound a bit "Eurodance-ish", but focuses on more 80's soundworlds such as sometimes using bells synths, and or such other 80's elements, sometimes some early techno-house and early eurohouse/early italo-dance elements such as techno synths, and pianos.
Examples: Sophie - Stop The Music (80's bell sounds in the riff), Annalise - Summertime (techno sounds in the riff), annerely gordon - luck lucky (piano house sounds), , AND ALL OF TODAY'S EUROBEAT SONGS (a combination of one or more of: Italo-disco vocals and sounds (sometimes calm atmospheres (aishu Eurobeat), HI-NRG influenced powerful choruses, eurohouse pianos, techno sound worlds, eurodance thump baselines)
EARLY TECHNO, EARLY TECHNO HOUSE = late 80's to early 90's. hard synths, such as brasses and leads. dark, powerful atmospheres. more focus on sounds with usually very little vocal work, if any at all.
EARLY EUROHOUSE, EARLY ITALO-HOUSE = as early as the mid 80's, until the early 90's. disco baselines, mixed with elements of piano, completely synthesized.
Examples: Marshall Jefferson - Move Your Body, Black Box - Ride On Time, Marky Mark & The Funky Bunch - Good Vibrations, East Side Beat - Ride Like The Wind (piano mix)
EURODANCE/EUROHOUSE, EARLY ITALO DANCE = early 90's to mid 90's, some productions as far as late 90's as well. maybe sometimes share similarities with early eurohouse and early italohouse with some piano melodies, and sometimes piano sounds are omitted completely and use a harder techno synth sounds. "Thump" sounding basseline. Stronger beats and baselines than early eurohouse or early italo-house, rapping sometimes included. Sometimes sounds like a mix of early techno house fused with early eurohouse or early italo-house, but with vocals and usually rapping as a bonus. Some songs might incorporate a reggae sound to them as well. some songs may be very light, poppish, bouncy & fun as well.
Examples: alexia - me and you (voltage mix [piano sounds]), 2Unlimited - Let the Beat Control Your Body [techno sounds], Whigfield - Saturday Night [bouncy & fun sounds], Ace of Base - The Sign [reggae sounds]
LATE 90'S EARLY 2000'S ITALO-DANCE = heavier sounding than the early italo-dance and eurodance. elements of trance may be present. with a lot of vocoders used on the vocals.
Examples: EIFFEL 65 - Blue, other artists include Gabry Ponte, Gigi D'Agostino
If anybody wants more examples of each, I'm more than happy to provide them as well

I listen to all of these genres all the time.