If your on a budget Walmart have some good prices on them
I would definintly get one that has the automated swing it will be helpful when you need to put baby down to sleep or do other things. That's one of the items I have already started looking into reviews so I can pick one out. I'm also going to get a bouncer or rocker so I can easily take it with me when my mil watches baby.
I got myself a mammaroo as a friend recommend it to me and watching her baby in it was amazing he was so relaxed in it as they mimic the movement of mummy's cuddles and rocking motions. you can plug your phone in to it and change motions too its definitely worth having a look at one.
A baby swing was a lifesaver for me. That's the only way my daughter would sleep at night for 2 weeks. My daughter is 11 months and still will only take her afternoon naps in her swing. I like the ones that swing side to side...not forward and back.