Marc, Mikva, Shadz and TomTheTurkey are all underrated.

Abel
-Unique offensive style 1on1 and will go even at least almost every match in GS.

Majin
-He has greatly improved this past year by being active.

Aserus
-Another offensive juggernaut and by far the most underrated GS sparrer.

Xoss
-Didn't know him until we met in GST finals vs GTEAM and he was their best guy by far.

My list would be topped by people in Ventrue. Back in 2010/11 when i was fairly new to the game i was in Ventrue and the people in the guild such as Gambit,Death,Angelus and Selena Coterie were all quite good, Ventrue was never really known for there sparing but overall they were one of the top guilds due to loyalty and skill throughout all of the members--Aserus in my opinion is the currect top active underrated sparer--

Sharp, Gambit, Abel, Sinatra, Slayer, Livid and Kippy

in my opinion are underrated :P

Spodey and Tom are really underrated

^--- Super Kurosaki is one of the only underrated idevice sparrers who can rush well so I guess he's my pick.

Saw Livid sparring today, he's definitely underrated.

oh yeah, kinda forgot about that guy, I don't really know him and can't recall sparring him in the arena but he seems pretty good at GS

rainmaker - extremely defensive PC player hard to beat if you don't know how to blink.

10-9 on him today.

good to know.

abel won many gst in the past. not underrated imo
sinatra, kippy agree they are underrated.

Junior doesn't spar actively anymore, but towards the end of Mother and first year Alumni when he had his iPad he was super good + underrated

I don't think Junior was underrated at all. I remember he was always mentioned when people talked about best iDevice gsers.

No one is underrated when a lot of people call you good, with that being said here is my list.
From what people would tell me, "Why is he in guild", "He is just a sub", or "He is a selective sparrer".
Underrated Sparrers: Blaze, Fulgore, NK, Austin Koga are the only ones constantly being underrated, because they work really hard and have gotten very far. I realize that they don't shine much, but they can surprise you sometimes. I wouldn't go easy on them if I were you :D. I can't remember anyone else atm, but I think there were others.