What are you looking to use the laptop/iPad for?
If you want to do gaming, the laptop is better but honestly, getting a gaming laptop is kind of stupid. They're expensive and a pain to upgrade.
If you're actually planning to do any kind of work on the device, get a laptop.
If you want something for email, surfing the internet, and simple games, get the iPad.
I have an iPad 2 and I love it. I rarely pull out my laptop anymore (gaming laptop at that!). The iPad is great for traveling, great for surfing the internet and email, and there really is an app for just about everything you need. There are a few websites that don't work well with the iPad and that sucks, but for the most part I love my iPad to death.
There are other tablets out there, but for the price, the iPad 2 is about the best you can get. The droid ones aren't that great even though they're more open. They're either a funny shape or just not that good. While the iPad has its share of problems, it really is a great device.
-edit-
And just a note about the memory and 3G
I have the 32GB model and that's generally fine for space. I usually keep a few gigs of music and maybe 20 gigs of video and that's good. I don't know what you plan to store on there but if you want to save costs the 32GB could work. It really just depends on what you want to do. I don't usually have to store a lot of video on it because I use Netflix on it a lot.
As for 3G, you can pay for it monthly as you need it. I dont' have the 3G version because I thought it was silly but there have been times when it would have been very useful. If you're traveling a lot, it can be handy.