Blimey this thread has a few familiar names I recognise...
For me (in the midst of serious considering buying a PC to start playing BF and CoD), any new Battlefield game would have to be modern day. I agree with others that BF3/BF4 were my absolute favourites. Admittedly I'm slightly biased as I typically will only play infantry only on small maps - Lockers/Metro for example.
I still remember that night we went on a killing spree in Lockers with triple digit kill counts hah and many accusations of cheating IIRC.