Just because a patent has been granted doesn't mean it will be valid when tested in court.
And just because a patent sounds obvious to you, doesn't mean it was obvious when it was invented.
A case in point: The iPhone's slide-to-unlock patent was a novel way of unlocking a phone. Before that you had to press and hold a button, or press a button that was deliberately difficult to press.
Someone at Apple came up with the idea of slide-to-unlock, and they tested it and they coded it. Why should Apple have to sit by whilst other people steal their ideas? It might sound obvious to you now, given the prevelance of smartphones. But let's not forget that when Apple patented this idea, their phone was the only phone that was just a screen. Everyone else had a keyboard or a phone-pad for data-entry, so a swipe-to-unlock was genuinely a new idea.
I suppose for me the one big thing that does need to change in patent law is that I think patents regarding codecs and parsers should be changed to make it cheaper and easier to make interoperable software.
For example, whilst I have no objection to the inventors of H.264 patenting clever ways of quickly decoding software, or even clever ways or encoding and compressing video - I don't think they should be able to prevent people writing software that decodes H.264-conforming video.
Similarly I think that it's fair game for the inventors of DVD and BluRay codecs to charge hollywood royalties to allow movies to appear on BluRay. But I don't think it's reasonable for them to charge your DVD/BluRay software money to allow you to decode your content - hell, you've already given them the money when your bought the disk, you shouldn't have to pay twice.
It should be legal and proper for me to implement my own PDF reader or to write my own PDF writer without giving Adobe money (since PDF is a de-facto standard). I just shouldn't be allowed to copy how Adobe are doing the reading/writing.
I think the law should say if a format X exists such that X is a de-facto container for transmitting or storing data, such that it is likely that a company wishing to transmit or store data of that type will be compelled to read or write data in and out of that container, then it should be legal and free for any third-party to implement software that read or writes data in or out of that container format.
The makers of H.264 should be free to sell their own software that makes H.264 videos, and they should be able to patent how their software works. But they shouldn't be able to stop or charge you from opening and writing H.264s via other, third-party applications (like a browser).