I noticed there is no real reliable source of information out there to figure out what exchange is worth dealing with, so i thought i might be a good idea to start a list that you could update and comment

I splitted the exchanges in 3 tiers from the Best to high risk
It is based on my personnal experience and extensive researches taking into account feedbacks, transparency, corporate informations, WHOIS etc; please add exchanges, comment and update

TIERS 1 (LOW RISK SOMEWHAT LEGIT / GOOD SUPPORT / REASONABLY FAST WITHDRAWALS)

ACX            Australia
Binance            japan china
bitcoin indonesia        indonesia
bitcoin.de         germany
bitfinex            taiwan hk
bitflyerFX         japan
Bithumb            korea
BITSO                   Mexico
bitstamp         uk slovenia luxembourg
bittrex            usa
BL3P            NL
BTC BOX            japan
btcmarkets         Australia
cex.io            uk ukrainian
coinbase            usa
coincheck         japan
COINNEST         Korea
coinone            korea
coinsquare         Canada
cryptopia         nZ
dsx                           uk
gatecoin            hk
GDAX            usa
Gemini            USa
huobi         china
independent reserve   Australia
itbit            usa
Koinex            India
Korbit            korea
kraken            usa
LUNO (SA)         South Africa
okcoin            china
OKEX            china Belize
Paymium         France
Quadrigacx         canada
quoinex            japan sg (legit but manual withdrawal only during business days; very slow)
Therock trading      malta
Tidex                        UK / Russia
zaif            japan

TIERS 2 (MEDIUM RISK, POOR SUPPORT, SLOW WITHDRAWALS)

Abucoins         poland
Bitbank                     China
Bitbay         poland
Bitgrail                      Italy
Bitmex         Seychelles
bitsane         uk
Bit-z                         China
Bleutrade         brazil
BTCC            uk china
btc38                   China
coinmate                   UK czech
coinroom         poland
EXX                           hk
Gatehub                    Slovenia
Kucoin                       Hong Kong
Liqui          Ukraine
livecoin          UK russia
Mercatox         UK costa rica
Poloniex            usa
ZB.COM                   china

TIERS 3 (HIGH RISK / POTENTIAL EXIT SCAM / NO SUPPORT / SLOW-NO WITHDRAWALS)

Aex                           WHOIS protected
c-cex         Russia WHOIS protected
coinexchange            WHOIS protected
coinegg                   UK chinese / same than coolcoin   WHOIS protected
coolcoin         China / cayman WHOIS protected
exmo             uk lithuania spain
Gate.io         china WHOIS protected (bter rebranding hacked/inside job)
Hitbtc         Unknown, no corporate registration. hidden WHOIS
Mixcoins                   uk china WHOIS protected
Right BTC         Dubai WHOIS protected
trustdex                    unknown origin WHOIS protected
wex                 Russia (btc-e rebranding) FBI investigation pending
xBTCe         china WHOIS protected
yobit            Russia (Russian police investigation pending)