I built the T-34/76 1942 model, and although old, it was a great kit that had a ton of accessories. I slathered on a whitewash, loaded up as much of the included stuff that could fit, and called it done. Further up the time line, the M-48 is pretty nice. I really liked the M113. It goes together well but it has an interior, so it is a bit more involved. Some of the newer Tamiya kits have indy link or link and length track, so be sure to check to see what kind of tracks the kit you choose has. Tamiya has also released some of their older kits with new parts and PE bits, like their Sdkfz.222 and Semovente. The Semovente has link and length tracks, while both kits have some PE and new figures.
In any case, if you go Tamiya for your first 1/35th armor kit, you can't go wrong. Don't shy away from the older kits, as they build into very nice models.