Since I've personally contributed over 100 entries to the list below, and it now has reached the 200 count milestone, I opted to start a new thread in my control so better to represent the demise of Bitcoin-themed endeavors.
By doing such, I would no longer need to continue to bump the growing list that consist of not one, but two entries per inclusions due to have taken the time to alphabetize the entries so others can easily see what has or hasn't been included. All that'll be needed now is the master list in this OP, with subsequent posts dedicated to the offering up of additions and comments.
In time (as an ongoing project), I may tackle linking the entire list entries, along with adding to them their start and end-of-operation dates, also linked, accomplishing said feat all on one line per entry. I will also (as per projected) make sure that the list is alphabetically correct, along with the entity's name presented as accurate as possible, correcting erratum along the way as others kindly provide their inputs.
Seeking
A to Z (mostly B)
50btc
Active Mining Corporation
AllCrypt
Alpha Technology
Altcoin Herald
AMHash1
AMT
Aquifer
ASICminer
Atlantis
Atomic-Trade.com
AurumXChange
bASIC-mining
BDT
betsofbitco.in
Bex.io
BiddingPond
BIPS (Bitcoin Internet Payment System)
Bit-Bank
BitBitcoin
bitbook.biz
Bitcoin24
Bitcoin2CDKey
Bitcoin7
Bitcoinary
BitcoinCashout
Bitcoin Cloud Hashing
Bitcoin Development Fund
BitcoinForFlowers
BitcoinFX
BitcoinGunParts
Bitcoinica
BitcoinMax
bitcoinPool
Bitcoin Rain
BitcoinRealty
Bitcoin Rebate
Bitcoin Solutions LLC
BitcoinTraining
BitDayTrade
Bitfountain
BitFunder
Bitinstant
bitlc.net
Bitmarket.eu
Bitmine
Bitmit
BitNetwork TV
Bitomat
BitPantry
BitPing
Bitp.it
Bitscalper
BitSpend
Bittalk Media Ltd
Bittrivia
Black Arrow
BlackBankMarket
BrainWallet
Brasil Bitcoin Market
Brawker
Britcoin
BS&T (Bitcoin Savings & Trust)
BtcATT
BTC Buy
BTCFPGA
BTC Guild
BTC Mining Corporation
BTC on Tilt
BTCT.co
Btctip
BtcTree
btcxchange.ro
BTCZone
Buttcoin.org
Buttercoin
Butterfly Labs
c-7.cc
Cam 4 BTC
CAVirtex
CleanBit
Coinabul
Coinedup
CoinEX.pw
Coinlenders
Coin Mining Coop
Coin.mx
Coinport Exchange
Cloudminr
Coinographic
CoinTerra
Coinware
CryptoChange
CryptoDouble
Cryptomine.io
CryptoRush
Cryptory
Crypto::Stocks
CryptoXchange
Daily Satoshi
dcash.io
Deepbit
Dicebitco.in
Dice.ninja
DZ Miner Coop
EgoPay
Ellet
El Show de Bitcoin
Evolution Market
FastCash4Bitcoins
FeedZeBirds
Flexcoin
ForBitcoin
Gamma Bitcoin Fund
GaW miners
GLBSE
GPUMAX Technologies LLC
HashFast
hashie.co
HashProfit
HASRA
HashTrade
Inputs.io
Instawallet
Intersango
Justcoin
KCMOCOLO
Kronos.io
Labcoin
LabRatMining
Le Bitcoin Show
LendMeCoin
LIF
Liquid Nitrogen Overclocking
LiquidBits
Litecoin Global (LTC-Global)
lovebitcoins.org
Lunamine
mcxnow
MinerSource
Mining ASICS Technologies (MAT)
Mintpal
MMOExchange
Momento VPS
Moolah
Mt. Gox
MTRed
MyBitcoin
MyBitcoinTrade
MyCoin
NeoBee
Netsolus
Nimbus Mining
Novello Technologies
NXT-E
OGRR
Onedice.me
OneWallet
Paybase
Paysius
Paytunia
PB Mining (PiggyBack Mining)
puddinpop
Robocoin
rollin.io
Seals with Clubs (SwC)
ShareXcoin
Sheep Marketplace
Silk Road
SilkRoad#2
sirarthur.net
Take My Bitcoins
The Bitcoin Show
TimeToBit
Tradehill
Triplemining
Ubitex
updown.bt
Vekja
Vircurex
Virtex
Virtual Mining Corporation (VMC)
WalletBit
WBX
WeExchange
WMXchange
x-bt
XBTec
ZenMiner
ZigGap
1) Mt. Gox
2) Bitinstant
3) Silk Road
4) Bex.io
5) Buttercoin
6) Brawker
7) GLBSE
inputs.io9) GaW miners
10) SilkRoad#2
11) Butterfly Labs
12) CoinTerra
13) Mining ASICS Technologies (MAT)
14) Mintpal
15) ASICminer
16) Bitcoin24
17) HashFast
18) BTCT.co
19) Bittrivia
20) BitNetwork TV
21) Bitcoinica
22) Tradehill
23) Instawallet
24) AllCrypt
25) CryptoRush
26) bitlc.net
27) Intersango
28) bitbook.biz
29) PBmining
30) HashProfit
31) CryptoXchange
32) MyCoin
33) Bitomat
34) Bitp.it
35) Brasil Bitcoin Market
36) BTC Buy
37) Btctip
38) Bit-Bank
39) Bitmit
40) Sheep Marketplace
41) hashie.co
42) Moolah
43) Seals with Clubs
44) mcxnow
45) x-bt
46) Justcoin
47) KCMOCOLO
48) Vekja
49) Bitmarket.eu
50) MyBitcoin
51) Bitscalper
52) BS&T
53) FeedZeBirds
54) btcxchange.ro
55) CoinEX.pw
56) AMT
57) HashTrade
58) WBX
59) Coinlenders
60) Paytunia
61) NeoBee
62) HASRA
63) MinerSource
64) Alpha Technology
65) Coinedup
66) BitcoinMax
67) Evolution Market
68) The Bitcoin Show
69) El Show de Bitcoin
70) Le Bitcoin Show
71) Ellet
72) Take My Bitcoins
73) Coinabul
74) Bitmine
75) MyBitcoinTrade
76) BIPS
77) LabRatMining
78) BlackBankMarket
79) OneWallet
80) Virtex
81) BitFunder
82) Bitcoin Development Fund
83) Netsolus
84) Nimbus Mining
85) Coinware
86) LiquidBits
87) DZ Miner Coop
88) GPUMAX Technologies LLC
89) Virtual Mining Corporation
90) Active Mining Corporation
91) BTC Mining Corporation
92) Litecoin Global (LTC-Global)
93) Bitcoin Rain
94) EgoPay
95) Coinographic
96) AMHash1
97) Altcoin Herald
98) CryptoDouble
99) Cryptomine.io
100) Cryptory
101) Dicebitco.in
102) Dice.ninja
103) Lunamine
104) ShareXcoin
105) BitDayTrade
106) Labcoin
107) Kronos.io
108) Britcoin
109) Bitcoinary
110) Robocoin
111) updown.bt
112) NXT-E
123) WeExchange
124) BitcoinGunParts
125) BitcoinForFlowers
126) FastCash4Bitcoins
127) CleanBit
128) AurumXChange
129) WMXchange
130) Cam 4 BTC
131) Flexcoin
132) BTCZone
133) Bittalk Media Ltd
134) CAVirtex
135) MMOExchange
136) OGRR
137) betsofbitco.in
138) rollin.io
139) Paysius
140) Bitcoin2CDKey
141) WalletBit
142) Bitcoin Cloud Hashing
143) Liquid Nitrogen Overclocking
144) 50btc
145) Deepbit
146) ZenMiner
147) Aquifer
148) lovebitcoins.org
149) BtcTree
150) Atlantis
151) Buttcoin.org
152) sirarthur.net
153) Atomic-Trade.com
154) Bitfountain
155) CryptoChange
156) BitBitcoin
157) BTC on Tilt
158) LendMeCoin
159) Coin Mining Coop
160) BitSpend
161) BitcoinRealty
162) BitcoinCashout
163) Bitcoin Solutions LLC
164) BiddingPond
165) Black Arrow
166) Vircurex
167) BTCFPGA
168) ForBitcoin
169) Gamma Bitcoin Fund
170) BitcoinTraining
171) BitcoinFX
172) puddinpop
173) bitcoinPool
174) BTC Guild
175) MTRed
176) Triplemining
177) BitPing
178) Ubitex
179) Bitcoin7
180) LIF
181) Bitcoin Rebate
182) BDT
183) Novello Technologies
184) XBTec
185) Paybase
186) Cloudminr
187) Momento VPS
188) BtcATT
189) TimeToBit
190) Onedice.me
191) bASIC-mining
192) Crypto::Stocks
193) Coin.mx
194) Coinport Exchange
195) BitPantry
196) ZigGap
197) dcash.io
198) Daily Satoshi
199) c-7.cc
200) BrainWallet