General Welcoming:
* Inviting
* Hospitable
* Warm
* Friendly
* Open
* Cheerful
* Amicable
More Specific:
* Welcoming (obvious, but effective)
* Inviting (suggests a desire to be entered)
* Hospitable (implies generosity and kindness)
* Heartfelt (shows genuine emotion)
* Gracious (expresses elegance and politeness)
* Genial (suggests a pleasant and friendly atmosphere)
The best word to use depends on the specific context.
For example, if you're describing a physical space, "inviting" might be a good choice. If you're describing a person, "friendly" or "hospitable" might be more appropriate.