Well it depends on a lot of different factors, such as:
- technical specifications of your receiver
- size and type of your dish
- type and noise-rating of LNB
- your geographical location
for example, you will only be able to recieve Channel5 (Astra1) if your receiver has a Videocrypt decoder built-in; you will only be able to receive certain Scandanavian channels on Sirius if your receiver incorporates a D2MAC decoder and your dish is, say, 1m or more in diameter. Several middle-eastern stations on Intel602 are unencrypted but can be received from the UK only if your dish is at least 2m and you have a clear line of sight almost to the horizon. Many German premium & public channels still broadcast in clear analogue from Astra1 and can be received from the UK with a dish as small as 70cm (say). C-band analogue channels such as MTV-Idia on Pas4 can only be received using a large prime-focus dish and special C-band LNB.
And so on.
Check out Lyngsat ( http://www.lyngsat.com ) for a full listing of channels/sats/format/encryption.