You can get as creative as you want with reward ideas and tailor them to your show and audience. Here are a few examples from successful crowdfunders of things they offer at various reward levels:
 
$1-5:
Shout outs on the show or site
Thank you email
Access to patrons-only comments
Digital postcard/note each month
Early access to new episodes
 
$5-10
Monthly, handwritten note or special show postcard
Small show products (poster, sticker, t-shirt, book)
Name listed on show’s patrons list and a shout-out on a show
Access to patron-only bonus content
Participate in a closed fan Facebook group or monthly google hangout with the hosts
Receive special inside tips newsletter
 
$10-30
Patron can read a short message on the show, or call in as a special guest
Special show products or access to exclusive events
Free 30 minute consulting session with the host
Dinner with the hosts
Patron can determine a show topic
Specially-selected gift delivered each month
 
$30-75
Appear as a guest on the show
Choose a guest for the show and attend the recording
A personal thank you video from the hosts
A 60 second sponsorship of your product or service, read by the host
One hour videoconference with the hosts