I have my address+key and address where I want to send BTC. What is the easiest way to do it? I would prefer online service. Also without registration (or really simple). Is there any service where I can just add these 3 informations and that's it? Thanks.
If you prefer online wallet, you can get a blockchain.info wallet, and the registration is simple.
1. Go to
https://blockchain.info/wallet and create a new wallet.
2. Click Import/Export -> I understand, and enter your private key in the "Import Private Key" field.
3. Click Send Money, and send your bitcoin
I would suggest you to have 2FA if possible for better security.