That honestly depends on your level and class and if you were planning on just soloing or if you were wanting to start grouping or raiding. UF requires a group. However, and I'm not sure what expansion you last played during but, Seeds of Destruction has plenty of places to solo for anyone starting at 70+ really, as long as you don't mind running from higher level 3k+ hitters and only pull weak con mobs that hit for ~500.

Again, depending on the last time that you played, gear is really easy to come by.