Can anyone recommend me a reliable cryptocurrency exchange pln/btc or altcoins?
Maybe you should check BitBay or CoinDeal? Personally, I like CD, they have great variety of cryptocurrencies. I consider it as a really professional and reliable. Now, this is a great moment to register because CoinDeal have a giveaway and you can have CDL Tokens for free. If you want to know more about CD -
here is the article about its current actions.
CoinDeal is fine, I really enjoy it because there are coins which aren't available on other exchanges e.g. Futurocoin, also these tokens are great opportunity to encourage new users to CD