There are 1,469 crypto currencies currently listed on coinmarketcap.com and several more are coming in form of ICO(Initial Coin Offerings). Despite heavy competition, Bitcoin will remain the King of Crypto Currencies for several reasons:

First Mover Advantage: Bitcoin is the first crypto currency and hence will have first mover advantage. Whenever Media talks about Crypto Currencies, they talk about Bitcoin. It has become synonymous with Crypto Currencies. When people think of Photocopier, they think of Xerox. Similary, when people think of Crypto Currencies, they think of Bitcoin.
Merchants accepting Bitcoin: There are several merchants across the world accepting Bitcoin. It is the willingness of users and companies to exchange Bitcoin for goods and services that make it valuable. Here is a list of 100+ of them, sorted in alphabetical order:

1-800-FLOWERS – United States based online floral and gift retailer and distributor
4Chan – For premium services
A Class Limousine - Pick you up and drop you off at Newark (N.J.) Airport
Amazon – An online company that sells almost anything.
Apple’s App Store - Buy music and any app on the Apple AppStore with bitcoins
Badoo – Online dating network
BigFishGames – Games for PC, Mac and Smartphones (iPhone, Android, Windows)
Bing by Microsoft – 2nd search engine to Google
Bitcoin. Travel – a travel site that provides accommodation, apartments, attractions, bars, and beauty salons around the world
Bitcoincoffee – Buy your favorite coffee online
Bloomberg – Online newspaper
Braintree – Research firm
CEX – The trade-in chain has a shop in Glasgow, Scotland that accepts bitcoin
CheapAir – Travel booking site for airline tickets, car rentals, hotels
CoinMama: Buy Bitcoins with Credit Card
Crowdtilt - The fastest and easiest way to pool funds with family and friends
curryupnow - A total of 12 restaurants on the list of restaurants accept bitcoins in San Francisco Bay Area
CVS – A pharmacy shop
Dell - American privately owned multinational computer technology company
Dish Network - An American direct-broadcast satellite service provider
Dream Lover – Online relationship service
Etsy Vendors – Original art and Jewelry creations
Euro Pacific – A major precious metal dealer
Expedia. com – Online travel booking agency
ExpressVPN – High speed, ultra secure VPN network
EZTV – Torrents TV shows provider
Famsa – Mexico’s biggest retailer
Fancy - Discover amazing stuff, collect the things you love, buy it all in one place
Fight for the Future – Leading organization finding for Internet freedom
Fiverr – Get almost anything done for $5
Grass Hill Alpacas – A local farm in Haydenville, MA
Green Man Gaming - Popular digital game reseller
Grooveshark – Online music streaming service based in the United States
Helen’s Pizza - Jersey City, N.J., you can get a slice of pizza for 0.00339 bitcoin by pointing your phone at a sign next to the cash register
Home Depot - Office supplies store
i-Pmart – A Malaysian online mobile phone and electronic parts retailer
Intuit - an American software company that develops financial and tax preparation software and related services for small businesses, accountants and individuals.
Jeffersons Store - A street wear clothing store in Bergenfield, N.J
Kmart - Retail products store
Lionsgate Films - The production studio behind titles such as The Hunger Games and The Day After Tomorrow
LOT Polish Airlines – A worldwide airline based in Poland
Lumfile – Free cloud base file server – pay for premium services
Mexico’s Universidad de las Américas Puebla – A major university in Mexico
Microsoft – Software company
Mint - Mint pulls all your financial accounts into one place. Set a budget, track your goals and do more
MIT Coop Store - Massachusetts Institute of Technology student bookstore
MovieTickets – Online movie ticket exchange/retailer
mspinc – Respiratory medical equipment supplies store
Museum of the Coastal Bend - 2200 East Red River Street, Victoria, Texas 77901, USA
Namecheap - Domain name registrar
Naughty America - Adult entertainment provider
NCR Silver – Point of sales systems
Newegg – Online electronics retailer now uses bitpay to accept bitcoin as payment
OkCupid – Online dating site
Old Fitzroy – A pub in Sydney, Australia
One Shot Hotels – Spanish hotel chain
Overstock – A company that sells big ticket items at lower prices due to overstocking
PayPal / Ebay - Credit card / payment processor / Auction
Pembury Tavern – A pub in London, England
PizzaForCoins - Domino’s Pizza signed up – pay for their pizza with bitcons
PSP Mollie – Dutch Payment Service
Rakutan – A Japanese e-commerce giant
RE/MAX London - UK-based franchisee of the global real estate network
Reddit – You can buy premium features there with bitcoins
Sacramento Kings – Professional Basketball team out in Sacramental California (NBA)
San Jose Earthquakes – San Jose California Professional Soccer Team (MLS)
Save the Children - Global charity organization
Sears - Clothing and household products, electronic store
Seoclerks. com – Get SEO work done on your site cheap
SFU bookstore - Simon Fraser University in Vancouver, Canada
Shopify. com – An online store that allows anyone to sell their products
ShopJoy – An Australian online retailer that sells novelty and unique gifts
SimplePay - Nigeria’s most popular web and mobile-based wallet service
Square – Payment processor that help small businesses accept credit cards using iPhone, Android or iPad
State Republican Party – First State Republican Party to accept bitcoin donations
Straub Auto Repairs - 477 Warburton Ave, Hastings-on-Hudson, NY 10706 - (914) 478-1177
Stripe - San Francisco-based payments company
Subway – Eat fresh
Suntimes. com – Chicago based online newspaper
T-Mobile Poland – T-Mobile’s Poland-based mobile phone top-up company
Target – An American retailing company
TechCrunch. com – IT blog
Tesla – The car company
The Libertarian Party – United States political party
The Pink Cow – A diner in Tokyo, Japan
The Pirate Bay - BitTorrent directories
Tigerdirect – Major electronic online retailer
Victoria’s Secret – A lingerie outlet
Virgin Galactic - Richard Branson company that includes Virgin Mobile and Virgin Airline
WebJet – Online travel agency
Whole Foods – Organic food store (by purchasing gift card from Gyft)
with your money, for free!
Wikipedia - The Free Encyclopedia with 4 570 000+ article
WordPress – An online company that allows user to create free blogs
Yacht- base – Croatian yacht charter company
Zappos – Online retailer
Zynga – Mobile gaming
Digital Scarcity: There will be a limit on the number of Bitcoins available. It is limited to 21 Million Bitcoins. As more and more people across the world are willing to barter in Bitcoin, its demand will continue to rise. That is the main reason why we see future valuations of Bitcoin price skyrocketing.
Permissionless and Peer to Peer exchange: Banks have a say in whether or not you can spend your money or honor the transaction. With Bitcoin, user has the freedom and doesn't require permission from the banks to spend their currency.
Wide spread adoption: There are several Crypto Currencies, but none has wide spread adoption as Bitcoin, and it will continue to remain so. With increasing number of altcoins, it becomes messy which ones to use. Merchants can't keep supporting unlimited digital currencies. They are more likely to stick to Bitcoin, rather than supporting several different forms of crypto currencies. Users would be overwhelmed to exchange their fiat currency for several altcoins. To keep things simple, a line will be drawn on which crypto currency/currencies to be used, both from users as well as Merchants. Bitcoin will have its advantage here and hence will be adopted widely. Other altcoins have to justify why they need to be adopted over several other altcoins. Bitcoin will remain in a league of its own.
Branding issue for other forks of Bitcoin: Several forks of Bitcoin have come in place, some of them even claiming to be the real bitcoin, such as Bitcoin Cash. However, the moment they are branded as Bitcoin ___, they are not Bitcoin anymore. Forks will keep coming and will never stop, but users will like to have Bitcoin, rather than invest in Bitcoin ___. It is a lost cause in trying to compete with Bitcoin and say all users to move to Bitcoin ___ instead. Some of the forks that are currently available, are not even listed on several major exchanges such as Coinbase or Binance.
Reduction of fees with Lightning network: Lightning network will enable scalability issue of bitcoin and reduce the fees drastically. This will encourage Merchants to transact in Bitcoins