I would recommend a Tivo with the lifetime subscription. If you are only going to be an ota user, then the 2-tuner Premiere would be for you (it also works with cable). The two 4-tuner models are cable, using a cable card, only models. The Tivo offers a full 12 day guide and doesn't depend on iffy PSIP data. You can buy a refurbished 2-tuner model with lifetime guide subscription for $600 from Tivo. Tivo also has special deals available from time to time. Look at their site for more info.
You can also go the Windows Media Center route using a pc. You can go to the Home Theater PC section here at AVS Forums to get more info on those. They work really well, but they aren't for everyone. I happen to have a 3-tuner HTPC-based dvr and a 2-tuner Tivo Premiere for my ota recording needs. The pc solution can record off of ots, "clear" QAM and cable card (depending on which pc tuner(s) you buy.
There is also Simple.TV. It is a networked dvr that uses a Roku player to watch your recordings with. You can use it without a subscription, but they also offer subscriptions (1 year and lifetime) if you want a real interface. It only has one tuner though. And if you get more than one box to record more than one channel at a time, then it is more expensive than a 2-tuner Tivo Premiere. It can record ota or "clear" QAM cable channels.
If you're going to go with a satellite provider, then you have to use their equipment. No 3rd party choices with them.
In my opinion, the other dvr's available in the US can be glitchy and won't offer the full features dvr's like Tivo, Simple.TV or Windows Media Center have. I bet you wouldn't be happy having to record using a vcr-like interface. Remember, when you pay $40 for a dvr, you're going to get what you pay for.