Theres soooo many other "starter" snakes out there apart from royals and corns, however both seem to be one of the most popular and most documented species in captivity making husbandry research so widespread.
Personally I started with corns, then moved to boas. BCI morphs. I now have a few other different species - royals, western hognoses, sand boas and soon to be P. Baroni... I would not recommend baroni or western hoggies as a first snake for many reasons, one being both are rear fanged species.
If your worried about space then large constrictors ie burms, BCI's, BCC's, retics etc are a major no no!
If you lack experience with snakes in general or have not experienced fussy feeders, regurges and other health problems its an absolute MUST to find a healthy, well established snake. A yearling is your best bet.
Key factor in chosing a snake is to FULLY research the species, and decide whats right for yourself - taking every point of their husbandry into consideration. You can't go wrong with corns though, as safe as they may be.