I think like other people had stated - if you're a sports fan it's a no brainer. I'm not, so it's a little tougher. I had Comcast and Time Warner both. Here are my opinions:
channel line-up - other than the sports they're probably about equal. Cable did have more of the local digital channels - like the extra ABC, NBC, etc channels, but those extra channels were garbage anyway.
price - I've considered switching year after year and have always found them to be about the same - or leaning toward cable since I could plug as many tvs in as I wanted. If you have home phone and DSL then satellite wins, but if you have a cable modem (without or without VOIP) cable always won for me. My company put a landline in the house, which made DSL cheap, which finally made sat worth trying.
picture quality - even the non HD channels are very good quality on directv. I also get better signal quality since I switched
DVR - much better than the scientific atlanta that time warner uses - assuming you get the HR24. The other ones were better in capacity but the menu/channel lag is really annoying
On Demand - I like the streaming on demand that cable has better than the download on demand that directv has. Directv probably has more content that time warner though. Their interface is better than the crap that time warner had - at least when I had it. The only downside is that they don't have HBO on demand.
Other than that I'd say that cable wins in 3 areas: #1 you can plug into as many tvs as you want without extra receiver lease fees. that is worth a lot if you're jsut throwing tvs in rooms that you don't use a lot or don't want to pay for - guest rooms, kids rooms, etc. #2 you can generally get service without lease agreements, Eartly termination fees, etc. #3 the whole rain fade thing is pretty annoying. I guess there is nothing they can do about clouds, but I figured lost signal in the rain was something of the past, until I switched. If it rains you will lose your signal. I bet those expensive sport packages are great when they get rain fade! I never had signal issues with comcast or time warner, but where I l ive now I had a crappy municipal cable company and their signal would degrade for no reason at all. At least rain fade i can explain!
Where sattelite wins - Multi room DVR is awesome, the TV apps are cool, even though I rarely use them. The general interactivity of the system is pretty cool - like News and spots channels that show you 8 channels at a time, and the feature to see what the top 5 shows are at the moment. The hard drive capacity kills cable. If you get 24 series boxes, they are significantly better than cable. The older ones are worse in my opinion - they have better capacity and features, but the lag was so bad that it really left me regretting my decision to switch.
All around I am much happier with Directv then my local cable provider. I also like them better than I liked Time Warner. Comcast gives them a run for their money, but the multi room DVR and hard drive capacity still blows them away.