7 is probably the best place to start if you haven't played any before. My personal favourite is 8 but 9 is amazing, 4 and 6 are also great. 10 good for a first timer. The rest I'd say get around to after a finishing a few others.

Never played Bahamut Lagoon or Last Remnant, I'll give them both a look out. I have definitely been recommended Bahamut Lagoon before cos I remember not being able to figure out the patch haha (I was like 10) but should hopefully be good for it now.